Paint Coat Colors // Markings

Since I'm going to be trying to get into breeding paints, I was wondering what color(s) are considered rare/desirable, what markings are rare/desired, and just generally what do people look for color wise?

Rare colors are double creams, champagnes, and modified with roan or flaxen. Rare marking patterns are actually solid, with the least rare being tobiano.

I personally try to breed for roan, flaxen, and dun modifiers over cream bases C: