I guess the easiest, fastest painting to do, that lot of people will like, is a pastel on black paper.

   It's the high contrast that makes it look good, not necessarily the craftsmanship.   Remember this rule of thumb.   Leave 20 percent of the colored background paper showing.   Spray it lightly when you're finished, then touch up the highlights and leave it alone.  Leave an eighth inch of air space between the picture and the glass protection.