I found the idea for this activity here. Oh, and also only use the plastic bags if you are going to be supervising your child! I just added them in because we don't get the paper so we had very little of it in the garage, but had tons of plastic bags that my inlaws always seem to give us.
I also made up a sensory box (in this case, I almost think its just another term for "junk...") I tossed tons of stuff in there, mostly game pieces--from Rummikub, Dominoes, Sequence, Mancala, Scrabble, plus shape beads, cotton and pompoms, clothesmpins and a couple shiny plastic ornaments for good measure.
He is currently into stars since we put up the tree, so we set about to do a star collage. He has helped make these in the past but this time his helping equated to him continuously getting his hand stuck on the paper.
One final thing I did, in a fit of randomness, I decided to cut stars out of scrap paper and I taped them up all over the living room. It took a while, but he eventually noticed them and has been having fun taking them down, looking at them, and then "pat, pat, pats" them back onto the wall (which is what we say when we make the collages).