I've been having the same problem with my 3.5 year old. She does have bins too as I knew she would feel left out that her brother (2nd grade) had them and she didn't. We've done all the things you have already tried and she blows through them and then starts crying because she wants to do "more school". Yesterday I put on Letter Factory for her and that worked but that was only one day. Thinking of getting Horizons for 3's and I ordered some Rod & Staff pre-k material as well. I had no intention of doing anything structured with her at this age but she has gone through all of the busy bags, almost all of the Do-A dots, Kumon books and The HWT workbook. I can't turn my back on her with play-doh, clay or markers. Have you tried Wiki-Stix? DD likes those and they are clean.These are some great suggestions I will look into. She does art and science with us but we don't do that every day.