And we're NOT talkin' politics! Here's a thought to include on your "easel checklist."
Most artists have been known to struggle with a painting and have to figure out why it isn't working.
How and what you paint really doesn't matter here...it either works or it doesn't.
If all the obvious reasons fail to resolve the problem, then compare the overall volume of your three basic values:
Medium Values and
None of these values ought to be of equal volume in a painting.
Vermeer did it right. I removed the color above so that you could compare his basic values more easily.
Here are some examples in verrrry simplistic terms to illustrate this concept:
The above example "works" in that medium, light and dark values are unequal. Thus it creates an interesting tension (compared to the examples below that are completely boring).
All three (light, medium and dark) values are equal in this example...a no-no in painting.
This "doesn't work" either in that both the light and dark values are boringly equal. (However, it could be made unequal and "fixed" by adding a spot of dark into the light or light into dark.)
Vermeer's paintings "work" (of course) and his distribution of values is a factor.
The subject doesn't matter - unequal value distribution works the same way.
So when a painting doesn't "look right" and you cannot figure it out...
...consider how you have handled your values.
I'm a big believer in copying the Old Masters if you wish to learn how to paint in a classical manner.
They have so many lessons to teach us that are hiding in plain sight.