So who am I to tell you your business?

Nobody.

I picked up this game on launch day and have since dumped an unreasonable amount of time into it.

I've never gone bankrupt, and have three-starred every level.

A lot of my earlier hospitals are dumb, looking back, and so I decided to share some of my observations and strategies that helped me make them not so dumb.

Enjoy!

Training staff is the most important feature in the game. Rather than having jacks-of-all-trades you want masters-of-one. Hire level 1 staff with either no traits or one of the starting traits for a specialist you want. Staff lists should look as follows for a three-star sized hospital.

Doctors
5-10 GPs - Level 5 GP - Assigned only to do GP work, with as many offices as you have doctors. I got 3 stars on the last level with 10 GPs.
1-3 Medical Doctors- Level 5 Treatment - Assigned only to operate treatment rooms
2-3 Psychiatrists - Level 5 Psychiatry - Do I really need to spell it out?
1-3 Radiologists - Radiology + Level 4 Diagnostics - Assigned to Xray and MEGA Scan only (but only bother building the MEGA Scan). These are the only solely diagnostic doctor room, and therefore the only reason to have diagnostics on a doctor.
1-2 Surgeons - Level 5 Surgery - Duh
1-4 Geneticists - Genetics + Level 4 Treatment - Assigned to gene labs only. Treating people has a chance to fail, so it's more important to have levels in treatment than diagnostics for genetics work.
0 Researchers - Level 5 Research - Have 3-4 on one map, and as more research unlocks throughout the game, return to that map to research it quickly. Alternatively have one researcher and have them constantly research cash unlocks. Haven't looked in to profitability of this but it's unlikely to be high. Will likely pay for itself but unlikely to be a real income source. Needs further investigation.

Nurses
4-6 Diagnosticians - Level 5 Diagnostics - As many as you have diagnostics rooms.
2-3 Medical Nurses - Level 5 Treatment - AVOID pharmacy or injection traits. The extra 10% in one room isn't worth -10% generally. There are a lot of rooms these people will be working in, and illnesses for those rooms generally aren't hard.
2-4 Ward Nurses - Level 5 Ward Management - Ward nurses to beds should be a 1:3 ratio. Get two screens per ward, also. Patients take a while to change and will bottleneck at one screen.

Janitors
Less important, but prefer to have Ghost Capture, Motivation, and Level 3 Maintainance, with a single Level 5 Mechanic for upgrading machines.

Assistants
Not important at all. Have 1-2 assistants have marketing skills only and unassign them from all but marketing

Next to staff, rooms are also very important. Some would say more important. The debate rages.

On a basic level, there's no reason not to have every room provide for staff needs while being as small as possible. Hand sanitisers, coffee makers, sweet dispensers, and at least prestige 4 from gold certificates to keep all staff happy and on top of their needs.

Being above 80% happiness provides a 10% bonus to all skills and this pays off massively in the long run, especially as a low-level doctor or nurse will have about 40% treatment skill and will be killing one in three patients.

Staff walking from one room to the next takes a great deal of time. Days even. Rooms are really easy to move and assuming you kept them all as small as possible you'll have a tremendous amount of space by hitting three stars in a hospital. Once you start snowballing, expanding is cheap and you'll be making tons of money based off of what you already have.

Pretty early on (by the time you start needing more than two GPs) you should be thinking about how things are laid out.

I tend to have:
GP Central - A central location where your GPs are kept. Somewhere between 5-8 on them depending on the level. Patients will be constantly returning to GPs, so having these be central is vital.
Diagnostics Wing - Either attached to or very nearby GP Central, so that it takes very little time for patients to bounce inbetween. If more than one building is needed for this, have Nurse diagnostics and Doctor diagnostics seperate. The idea is that staff who work in multiple rooms should have those rooms be close together. Rooms which double as Treatment and Diagnostic (psych, genetics, ward) should be with these, so that patients who are there for diagnostics don't need to walk too far to return to GPs.
Doctor Treatment - Self-explanitory.
Nurse Treatment - Surgery can go here but not vital, as Surgical doctors don't interchange with other treatment rooms, but nurses do. I tend to have my treatment nurses assigned to assist with Surgery though I've read that the nurse's skills don't actually ever matter. These treatment wings can be further away as it should be a patient's last destination in the Hospital

Admin Block - Training, research, marketting should be here. Any rooms that patients will never have any need of. As far from the public parts of the hospital as possible.

Also a toilet and staff room in every building. The philosophy here is to cut down on staff travel times as much as possible.

This is a very general tip that leads into the next three. If something isn't working, find out why. Why exactly are queues building up? Is it that there are too many patients? Or are patients running halfway across the hospital to get to a toilet or vending machine? Are staff spending too much time walking around just getting between rooms? Figure out where things are going wrong and why. Most times you won't actually need to build new rooms or hire new staff. Just rearrange.

Patients do not prioritise their own care. They prioritise their base needs. If hungry, thirsty, bored, or needing the toilet, they will leave the queue for a room and deal with that need. They won't lose their place in the queue, however, and will hold up the whole room until they're done. As hospitals get bigger this becomes more of a problem if you only have a few places for these needs to be met.

You should have a toilet in every building, ideally with at least four cubicles. You should have two of each vending machine in each building with a bin for each pair. Split them up too, so queues don't blob up and cause traffic jams. Banks of arcade machines in every building should provide for boredom. I find them the best as people will queue up for them and will eventually turn a small profit. No need to maintain or restock either. Gift shops and newsagents make better money but aren't space-efficient and need staff to work. Feasible in GP central maybe, if you can spare the space, but not everywhere.

You don't have to treat every patient and you aren't expected to. The No Deaths award is by far the most difficult to achieve after your first or second year. Some people are just going to have to go untreated.

When queues have built up (and they will), go into the room view and check who's waiting. Patients with no diagnostic progress should be sent home. Cull the reception waiting queue. Don't take on new patients when you're already struggling to provide. Look at patients. If there are any with visible diseases that you aren't ready to treat at all, send them home. This is also a general tip for how to succeed in the early game. Don't build too many rooms too fast, and anyone who looks like they need high-level expensive treatment rooms can go home.

Check the hospital-wide patient overview regularly and send home anyone who has red or orange health and is still bouncing around diagnostics. Reprioritise lists so that high-diagnosis lower-health patients are seen sooner.

The worst position you can be in is for all incoming patients to get to 80% diagnosed and then run out of health. Diagnostic appointments give money but not enough to turn a decent profit. Treatments are where the money comes from. Best to give up on some of the helpless or excessive patients so that some can actually be seen all the way through to treatment, and then when you have more money in the bank from those treatments, expand the facilities.

Somewhat related, emergencies can be a godsend, assuming you have the correct treatment room. 4-7 patients that come fully diagnosed and ready to treat can be worth a lot of money in a short space of time. If their 90 day timer isn't met, the patients don't die or leave, and still wait for treatment. You only need to successfully cure more than half of them in time to get the rep boost and a $10k bonus, and only take a rep hit if this isn't done. Even if the treatments fail and they all die, at least they paid!

This is the last of the "use your eyes" tips and is kind of a more vague observation. I can't pretend to fully understand the diagnostic system or how and why certain rooms are chosen by patients to be diagnosed. The only thing I can basically say for certain is that after the GP's Office, each diagnostic room will only be used once by a patient. As far as I can tell, there aren't any rooms that are necessary for diagnoses of certain illnesses. In theory, any and every disease could be diagnosed solely by trips to a sufficiently powerful GP, a powerful General Diagnosis, and a powerful GP again.

Look at how each room operates and how effective it is. Pay attention to the animations that play out and how long they take.

In summary screw you, Fluid Analysis. The room is expensive, the animation is glacial, and patients are sent with as much priority as the far faster General Diagnosis and Cardiology. After a few hospitals I realised I'd have to either build three of these things or better yet none at all. Patients seem to randomly assign to diagnostic rooms after a GP appointment. Even early on, when each diagnostic appointment only gives around 10% progress, you can quite easily make do with General Diagnosis, Cardiology, Psychiatry, and a small Ward.

In the same vein, screw the Gene Lab. The animation is long, it requires a specialist trait to operate, and the fact that it's both a treatment room and diagnostics room mean that patients will flood to it. All in all, massive queues. I tend to avoid building one until I have the funds to build two and fully train a doctor for each one.

Cafes are also large wastes of time and patient queueing.

Different rooms have different diagnostic strengths as well. A MEGA scanner is far more effective than a General Diagnosis. As your staff hit the higher levels, make sure that your rooms aren't standing idle, and if they are, sell them off.

Alright now, we're at Dark Hospital Strategy Hour. For these Dark Strats you will need encyclopaedia bookshelves and medicine cabinets. You'll also need a lot of money. This is something you start doing once the snowball has started rolling, in order to kick it into high gear.

Most people use the strategy of spamming gold star certificates about to boost room prestige, since boosting items stack additively.

This can be taken to a logical extreme.

Presenting: Teaching Neo Kung Fu By Uploading It Directly Into His Brain

Get a Training Room, make a teaching area about 3x3, and then make the room much much larger. Like make it 10x3. Fill this empty area with anatomy models and/or Encyclopaedia Bookshelves 2. This will cost several hundred thousand to do, but once done will leave you with a training room that can train any skill in around 10-15 days. Massively cutting down on training time like this means that your staff, especially your high-level staff who are likely doing the teaching, will be kept from working far less, meaning far fewer build-ups of patients in their absence. As long as there isn't an active emergency, anyone can be trained at any time without fear of causing many deaths by delays.

I've seen some people recommend this be done with anatomy models but I don't agree. They have the advantage that they don't need to be accessed from the front but you can fit fewer of them in the same space. 2 Bookshelves giving 8% take up very slightly less room than 6 Models giving 6%.

Finally: God is a Medicine Cabinet

The theory is the same as above. Spamming items giving additive bonuses to vastly improve a room's effectiveness.

Filling a GP diagnostic room with medicine cabinets to boost the diagnostic power. But also making that room absurdly large so you can fit ~80.

I've yet to test this on a large hospital but in theory far fewer rooms could have a much more dramatic diagnostic effect. I've tested it on Flottering and most people's initial GP appointment gives them 100% diagnostic progress.

This could also be used to boost treatment powers of rooms, extremely useful if you have a lot of patients dying after treatment due to low staff skill, and for some reason care about that happening, though of course the best strategy in this regard remains upgrading machines and levelling staff. .