I simply download pictures of whatever mobs I want to make and minimize them to an appropriate size and print out a sheet of them. Here's an example of a group of kenkus that I made a while back.
Then I use self-stick furniture pads & a round paper punch to make custom tokens. I've found that with my particular punch it's better to use a thicker paper, like a cardstock or construction paper.
Then for storage I simply put them into a fishing tackle box. I've made several hundred that way.
for large creatures!
The hole punches are pretty cheap on amazon ($11 for 1", and $12.50 for 2"), so even if you only deal with a few dozen large creatures over your DM life, it could still save you a decent chunk of time. But I'd totally understand if it's not a regular thing for you/your campaign(s).
For me, because I play on a whiteboard on the wall instead of on a mat on the tabletop, I instead use 2" per 5ft so that my players can more easily see everything.
I also print a lot of doubles for each token in different colours. This means that each mini has a unique colour (or different hair, weapons, etc). Which gives me flexibility to represent different setups for a fight, and it helps me keep track of each creature's hp without having numbers on every single mini.
To store and organise all of them, I bought some 3-ring binders, and clear photo sleeves. I also "borrowed" a sheet of sticky labels from work.
Originally I just used one envelope per monster type, and rubber-banded them together. But I found that got really annoying to deal with once I got to like 15 different monsters - an alphabetised folder is much faster and easier to flip through.
