Advice from my professor:
Work on the backgrounds, make them shimmer. (Can I use glitter?)
Do at least five paintings at a time.
A square landscape is difficult.
Look at the work of Rafael.
Use less oil, more turpentine.
Advice from my student-collegues:
Don't do them too big!
Use the overlays!
Look at the work of Alexandrine Hristov--the Moldovan singer-painter--your work looks like hers! Listen to her music while you paint!
You have the concepts, now you just have to do the painting--the easy part.
Your hands know how to draw, now you have to teach your arm to paint.