Everyone uses solo cups with soil. Cheap and easy. Oh, baby.
I got a tip from an old hippy. Retired Marine. So I claim no ownership and give this to you.
Solo cups are so cheap, why not make it easy. Start with a clear cup, Use 2 per plant. Poke holes in the bottom of one, for drainage- I use a soldering iron. Then cut the second- cut the bottom out and slice it up the side. When the time comes for transplanting, just drop the inner into your new pot and the cut cup come out without a fight.
It a delight to use and you won’t through another one away.