i'm one of those people who start out with a super basic idea to test the waters, but i try and also make it clear that if the artist wants more details, i can pile them on as much or as little as they want, which... does that help? (i genuinely worry about these things and i just don't want to be that person who sends someone into an anxiety attack)

Plenty of artists don't give artistic freedom/liberty as an option so i feel like people wouldn't mind if you made that change too. it's not worth it if its causing grief

I have not taken commissions in a hot minute, but I have learned from other artists to include in my ToS that if I'm required to come up with a design, it MUST have refs for me to work off of. So I'm not stuck, hours or days on end wondering if the design would be to the client's liking or not. That I will take liberties here and there, but if I have to come up with a whole new design without any real refs, then it's a no go.

Might suggest going about it the same way with your ToS.

Honestly just saying that that's how you feel is extremely helpful; because some artists are the opposite and resent having to meet specifications exactingly. People saying upfront 'the more specific the better' or 'the more creativity I get to put in the more effort I'm GOING to put in' would solve a lot of problems.

Thats a good point! I'm probably going to add that addendum in when I update my TOS! I do not like being the one coming up with a commission idea or character design, feels like the client should be the one doing that bit of the work.

that makes sense, or sketching a rough doodle or posing 3D models via Design Doll to show you what they have in mind on top of the character refs and description

It's good you say this, communicating what you really need from your commissioners is always a challenge. If you leave it open as an option, people like me will go for it, even if I had an idea in my mind, just because I like to give artists free reign to make adjustments for what they think looks good. Ask for more details, if they give you something impossible or hard to do, you can always suggest alternatively. Some artists will send out a super rough sketch for approval (if you think that would help) just make sure to build it into your pricing so you don't undervalue yourself <3