For me at least when I had tons and tons and tons of commission work piled up i just took it in school hour sized bites. 50 minutes of work then 10 minutes break, and in the end if it's commission work at least for me I didn't so much worry about if I liked it persay as long as I knew I put the work in and didn't half ass it, if the customer liked it I was happy.

Now for personal work dissatisfaction with art is a bit trickier, for me at least I really​ liked to paint another model again and try and see how I could one up myself kinda like how people do yearly redraws.

That's what I personally do when I need to get myself in gear with painting. Hope it helps.

Thanks for the advice! I'll take on that hour sized bites idea and see how it goes o: