Favorite Technique is paper layering.. pretty much do it on all my layouts. I like it because it allows me to play with texture and colors. (and adorable paper) I think paper layering is an easy technique to master as long as you remember two little kind of like guidelines (never any rules).
1. Less is often more..

2. Try not to make two pieces of paper the same size.. it is best if they are different widths and lengths.