and because cap galleries used to have the helpful random-caps feature.

omg I'd forgotten about those! I've just been capping myself for years, but yeah, that used to be a thing!

Is it an eternal struggle to not hate your icons (based on the great stuff others make) or can you grow out of it?

Aww I'm sorry you feel that way :( I'm grateful to be completely laid-back when it comes to most of my icons. (I'll usually only push myself if I'm entering an icontest or if a rare mood strikes) My extremely low bar for posting a batch is if I have six decent ones to put outside the cut lol.

If it's a particular effect you're wanting to learn, don't be afraid to ask the maker though. Most are happy to help! (or look for old tuts)