First and foremost:
1. Do not send me points before I have asked for them
Nearly every person who has commissioned me in my experience on this site has tried to do this. At best, I'll be annoyed at you. At worst, you're getting your points back and I may not even do it. I try to make it clear when I accept your commission not to pay until i finish, but it still happens. This brings us to my next point.
2. Don't automatically assume I will do your commission
It's not often that a refuse one outright, but please don't assume I will do it. Things happen. My life happens. It's not a guarantee. Please, it's just more polite to ask.
3. Be specific
I can't read your mind. More detail is always better. [Your character] getting kisses from [my character] is not all that specific or useful. Do you want certain poses? Backgrounds? Scenarios? I like ref sheets, and I like getting as close to what you want from me as possible without having to artistic-freedom my way through your commission.
4. Be patient
Anyone who has commissioned me recently knows that it takes me a while to do. "A while" can be as long as a few months if that's just how busy I am. I'm trying to be better about it, but again, life happens. If you're not willing to wait, find someone else who's faster.
5. Ask for my prices
I realize they're not super accessible, especially when my Core runs out. That being said, having a wad of points appear in my notifications is weird and uncomfortable when I have to give them back to you because you didn't check first. If you ask for prices, I will give them to you. If they ever change, I will make a journal about it. Just ask. Please.
I'm not trying to target anyone, but it's a bit annoying to see the same things happen over and over. I don't really get a lot from doing this. I pretty much just get enough points to be able to gift a Core membership during the deal that runs at the end of the year, and maybe something small for myself here and there.