This is to make sure that you do not get grabbed/clawed even if your melee hit did not kill or you simply missed the hit.

Exceptions are when you are very confident that your melee swing will result in a hit that kills, in which case you are free to skip the shove to save some stamina for better things.

Shamblers are slow. They cannot be a threat to you unless you give them the time to become one.
Do not give them the time to surround you! Walk around the Shamblers as soon as it is safe to do so before you lose the chance to do so.

(This is also because certain spots of most of the maps will infinitely respawn zombies)

Do keep an eye out for where you're going though! You don't want to walk directly into an even sticker situation.

Stamina is critical in this game.
You can't melee without stamina.
You can't shove without stamina.
You can't run without stamina.
Keep this trick in mind and your zombie-killing will be much more efficient.

You don't need to sprint. Save that stamina for better uses.
Either find opportunities to strike them down one by one with melees that are capable of one-hit kills, or have teammates help you (if they can).
If you are waiting for a certain objective, you can just keep stalling and "kite" them around without taking the risk of dying to the horde if you must.

If you did not know, pressing "H" holsters your item at hand and holds out your fists.
A punch is the most efficient way of taking care of a Crawler without wasting any of those precious ammunition, and it's much faster than melee weapon swings.

If you did not know, pressing "U" (by default) unloads all rounds of your gun's current magazine. You should do the same to all the guns around you that use the same ammo type as your current gun.

Prioritize ammo over melee when your inventory is full and need to make a choice between keeping ammo or melee.
There is no way around the fact that guns are better at keeping you safe than melees no matter how good the melee is. Unless you either have a very bad aim or you don't know how to refrain yourself from shooting anything that moves.
Exceptions can be made for a Machete in the hands of an experienced player, or a Hatchet if you really just can't live without a melee.

You will find yourself running out of ammo very often if you do so.
Exploit the slowness of the Shamblers.
Remember, you are clearing a path, not an entire area.
Do it fast too before they surround you and close up the gap you just made.

If you are a good aim, consider hipfiring over ADS shots when using the Smith & Wesson 686 Revolver. You are completely vulnerable and not able to do anything else such as shoving while cocking the revolver, which can make things end very badly for you.
Not to mention the much faster fire rate without the cocking animation.

If you are on the run, prioritize pistols over rifles of the same ammo type to save your inventory space.
If you are on a hold out, however, you sure can prioritize rifles over pistols for their superior killing capability.

Machetes are the only melee that can one-hit kill a Runner out of all the "light weight" melees.
Its light weight also means it can last longer before its user is out of stamina, as well as having a much faster swing speed compared to the heavy melees.

Among all the light melees that can guarantee kills with two-hits in the head, Hatchets take the least storage.
Hatchets' excellent damage also makes it an easier melee to charge up an one-hit kill compared to the others (except Machetes which can do the same even faster).

Although powerful on hit, heavy melees take up a lot of inventory space, have low swing speeds, and take a lot of stamina to use; making them unreliable in many situations.
Unless heavy melees genuinely fit your play style better, it is recommended to keep an eye out for the light melees that can guarantee kills with two-hits in the head. The following is a list of all of said melees:

- This melee does not really belong to this list but I feel like it deserves a mention.
- This is technically a heavy melee but it does not take as much stamina as the other heavy melees and it deals very good damage. However it is recommended to look for replacements as soon as possible due to the very large amount of inventory space it takes.
- Best used at the start of the game where you barely have anything else to use.

- It is recommended to go for light swings only due to its lower damage compared to the others. The amount of time it takes for you to charge up an one-hit kill with Lead Pipes is just not worth it. Despite its low damage, it still guarantees a two-hit kill.
- Can equip Maglite on offhand.

- A pretty decent melee. The only downside of this melee is the larger amount of storage it takes compared to the others.
- Can equip Maglite on offhand.

- Many new players actually do not realize that E-Tool can be folded with a right-click. The unfolded version has a greater stunning chance on hit but that is not really what we are looking for here (especially when you are supposed to have the habit of shoving after every melee hit). E-Tool also does not take that much storage space.

- As mentioned before, it deals good damage and it takes very little storage.
- Can equip Maglite on offhand.

- As mentioned before, it deals very good damage and it does not take as much storage. Its capability of one-hit killing Runners is also what makes it one of the best melees.
- Can equip Maglite on offhand.

(The Dual-Barrel Beretta Perennia SV10 Shotgun is obviously an exception to this)

In NMRiH, you would always port load your shotgun on the first shell if your mag is completely emptied, which makes the reloading process take significantly longer.
Avoid it by counting shots and reload before the last round is fired.

If your gun can penetrate multiple targets, make use of it!
This both improves your killing efficiency and ammo efficiency.

Practice makes perfect!
How do you know if you have mastered all of these tips and tricks? By performing solo runs!

My favorite map is Chinatown. Not only are there plenty of ammo laying all over the map, there is also a gun shop very close to spawn.
The difficulty of this map is just about right. It is challenging enough to test if you have what it takes to survive through a map on your own, but also not too difficult you can barely beat the map without help.

Keep performing solo runs on good solo maps such as Chinatown until you can confidently beat it on your own.
My first Nightmare run on this map was solo, and I managed to beat it without taking any damage. It is only because I have kept all these tips and tricks in my mind and performed them all as perfect as possible.
I believe that if you master these tips and tricks in this guide, you will have no problem doing the same as well!

This guide, of course, is not a handbook of rules you must follow. These tips simply come from my own personal experience on this game, and they work for me.
You are absolutely free to make your own adjustments to my play style to fit your own.
Anyways, I hope this guide can help you, even if it's just a little.