Shining Stars - simple tape design tree, with star garland. Washi tape would work well for this, as it wouldn't mar the wall paint. I just picked up some wide white washi tape, with "Merry Christmas" printed on it.
Milagros from Mexico - Cut shapes from disposable foil pans, place them on a piece of cardboard or a stack of newspaper, and use a pushpin to create punched patterns. Add a length of string for hanging. (via FamilyFun Magazine)