T.A.
My daughter loved the foam stickers at this age. They have them in all kinds of themes, shapes, etc. They are pretty affordable. I got a tub of them for about $5. They can stick them onto a large foam sheet or construction paper or a tin box, or they even visors and door knob decorations, etc. They are easy for them to peel as well much easier than regular stickers. Plus easier to hold as they are larger. It would keep my daughter busy for a long time =) And it is easy for mom as well. No prep time, just stick everything out. Easy to clean, usually involves picking up the backings that came off of the stickers.