As a commissioner:
-Being lied to. Just be honest, and don’t promise deadlines you can’t keep. I remember once I commissioned an artist who told me repeatedly my commission was being worked on over the course of 5 months, and then the final result (with no WIP) was of my OC in an outfit I uploaded only a week before I received the commission. I’ve learned to be a bit tougher in asking for actual WIPs rather than just being like “thanks for the response I look forward to seeing the art” about it.
-having to chase an artist, sometimes across different social media accounts, for an update.
-unlimited slots on inexpensive commissions, AKA if you’re not in the first 10 to get a slot then you might get your art in 3 years if you’re lucky when the artist burns out due to an impractical workload.
-a stupid TOS with unprofessional clauses like “no refunds ever” and “I can cancel your commission and partial refund/no refund,” there are a few incredibly skilled artists I have passed up due to having revolting TOS’s, since even though you can’t enforce illegal clauses, it tells me that the mindset of the artist might be troublesome to deal with.
-having to describe the exact image I want with exact pose references down to the last detail - I can understand why artists do this, but unless it’s a custom/reference sheet, I feel like I’m just punching what I want into an art-vending-machine instead of paying an artist for their skill, which includes some creativity.
-paying a detailed character fee and then having the details missing/wrong.
-people who will draw het but not same-sex relationships.
-public/comment commission applications. Beyond basic slot claiming, I hate this. I don’t want to post my PayPal address or unwatermarked character art publicly.
-“if you so much as LOOK at me while I’m working on your commission I will SCREAM” - this has never happened to me but there are some artists that give off this kind of energy...
As an artist, nearly all of my clients have been excellent superstars!
-getting creeped on by a person asking for a commission. And on a less terrible bit still irritating level, commissioners acting like they deserve friend treatment after I’ve drawn an anime picture or two for them.
-when NO information is given, like I get a reference and 2 words, or I’m told to draw them smiling - if the commissioner is happy that’s all that matters but I feel guilty for not delivering my best work sometimes.