Nobody talks about how much timing matters too. Whatever was coming out when you first got into comics becomes your baseline for what "good" looks like, even if it was mid. Your roomie's shelf plus whatever year that was pretty much locked in your tastes before you even knew what you liked.

The real skill here is losing customers in a way that makes them think it was their idea. You could try framing it as "materials and scheduling fee" instead of deposit, sounds less scary than handing over half the cash before a single line gets drawn. Milestone payments work great when the job is big enough to break into pieces, but if the whole thing is one cover image, congrats, you just invented a two part job with extra steps. Maybe split it into thirds instead, so the first check stings less while you still get paid for early work. Repeat customers who pay fast are basically gold, so maybe give them the old terms and save the 50% rule for new folks. The ghosts were never going to pay anyway, you just found out sooner.