I will tell you a quick way to make a lot of BLC coins, but first let me get a disclaimer out of the way. This is definitely the most efficient way of getting BLC, but I am not quite sure at what point in the game it starts to make sense. I spent a lot of time farming leaves AFK so I am not sure when this strategy will become super viable. But I believe that it will probably be viable after you aquire first few items that we will need.

I recommend saving up 1m BLC coins to first aquire the ability to buy pets and then buy Foxo. This cute little thing will make your BLC farming a lot more enjoyable and easier.

I believe that unique leaves are extremely useful so you should get those ASAP. I reckon you will be able to find a guide on how to get each one by a quick google search. More you earn the better, but the most important one for farming BLC coins is Ghost Leaf. You can get it by using the Blowfish while you're in the space map and having 1d Cosmic leaves. This will be a lot easier after you've already spent quite a bit of time farming reguralry.

After you do a Big crunch, you want to go to the Void, where you will be farming enough leaves to buy you flasks, that will then turn into better ones until they unlock Exotic leaves. After you unlock those, you want to either go to The Mythical Garden (which will later also give you Mythical leaves) or at least to The Abyss. Honestly, I would recommend spending 50 m BLC coins to get The Mythical Garden, since the Mythical leaves also have some options to upgrade your Big crunch reward.

You want to upgrade flasks asap to reach the Strange flasks that can eventually unlock Exotic leaves. Once you get Exotic leaves you farm them asap on either The Abyss or The Mythical Garden. You buy out as much Moar BLC as you can, before the point that it takes you a while to get the next level of Moar BLC. The time for getting the next Moar BLC level shouldn't exceed about 30 seconds. Once you get to that point, you do a big crunch and repeat. This strategy made me about 100m BLC in about 80 minutes but I believe it is possible to make even more BLC in less time.

I would like to mention some things that you will certainly not regret getting before you do this method of farming. I recommend buying every sort of autoupgrade (both flasks and leaves). This will make this method INSANELY more efficient and faster. Definitely get the Crunchy coins upgrade from BLC shop, since that means you can get both Prestige coins and BLC after you do a Big Leaf Crunch. Other possible upgrades from BLC such as BLC++ or the upgrades for rewards, printers and converters are also incredibly useful.

Certified femboy: I would suggest saving up enough blc to get "unlimited printer ink" which makes it so that your printers are immune to blc, then in the mythical leaf section buy the "printer of printers" it gives +1 to every printer for free. this means you get 1k printers which give you around 30-50 mil exotic leaves per second, this makes things a boat load easier because with the 3x bonus you get 12m blc almost every 5-10 minutes, if you dont have the bot for the leaves i suggest getting it after getting the coin bot(disable if you dont have the autobuy priority device) and the autobuy priority device. what this device does is makes it so that you have control over how much upgrades to put into certain items, for example you can set it to upgrade to 20 and it would upgrade that option to 20 as soon as you walk thru the leaf portal. no more, no less, and you can make it so it automatically buys the unlock options for flasks/trees/leaves, exc, so you dont have to. it just upgrades to what you set it to which makes it really good. the automatic coverter starter is good for its price too so you put in the least amount of effort for about 2 mil without the 3x, it just takes a bit longer. im making around 20 mil blc every 5-10 minutes using this method.

Thank you guys for reading this guide, it is the first guide that I have ever made and I hope it will be useful to you and that you liked it. I wish you all good luck in blowing leaves and please like this guide if you found it useful.
I would like to ask you to rate and review this guide if you found it useful!
Also, this guide was made back in the day and I am currently not playing the game so there's been plenty of updates (I hope). That being said, there is probably more efficient ways to get there or even further. Try to experiment! You will definitely figure something out!
Thanks for all the love in the comments, have fun blowing leaves!