Omg im so sorry I haven't been super active on ask OTL Um, honestly im new with commissions so I had the same problem! I tend to get my art finished rather quickly though, but just be realistic about your time frame? When you set up commissions maybe make a note of how long it usually takes you, and try to send plenty of progress reports along the way!! I think it's mostly just the more you do it, the more you get a feel for your own rhythm? Sorry if I'm not incredibly helpful;: if you need any help though don't hesitate to ask! I'll do my best!! (And I'll try to be more active on here, too orz im so sorry;;)