Clients that ask you to build X and then when you ask about said details to know everything up front, you get a deer in the headlights look.

I get it, not knowing right away is fine, but 5-6 months later and still "not knowing", being absolutely lazy with no responses to questions or just dumping the work to me to figure out from whatever source material you got it from and force me to crunch to save your ass isn't fun for me and I really don't give a shit about how much praise you give me publicly for the job I did.