Infants, pacifiers or little blankets. You can make cheap and easy ones with fleece.
Older kids, how about hand knotted friendship type bracelets (they are back in style) or bookmarks? Cheap and easy, and you can make them in a variety of colors and styles so kids can choose one they like that matches their style
One thing our church did for children in a foster group home, was made them all pillowcases. We did lots of different colors and fabrics and they chose their own. So many kids don't even have a basic pillow to call their own. They loved them and it was a relatively easy and inexpensive project. Especially if you do them travel pillow size and stuff them with the travel or mini pillows.