Know when to quit
I painted this nifty little flamingo face yesterday. I was so pleased with how it turned out! So pleased, in fact, I thought I'd try an owl face. After 20 minutes of trying to sketch in a little owl face that is 6"x6", I got frustrated. I thought, "ok, let's try a different bird." I wiped off the owl and thought I'd go for a heron. I spent a solid hour on a 6"x6" heron.
I hated it.
Couldn't be saved.
Ready to throw it out the window.
I wiped it all off. But, you know, in the middle of the owl, I thought, "you need a break" to which I retorted, "cram in as much as you can while the kids are out of town."
Sometimes you just have to stop and realize you aren't making widgets in a factory. You are making art. This kind of art, in particular, requires a high degree of concentration to get all the color accurate whilst working with tiny little brushes. If you're not there mentally, you just end up with junk.
The takeaway is: listen to yourself.