Sometimes I really love oriental trading! They used to have these DIY fans...they might still have them. We just used water color sets that the library already had. I gave each kid a fan, water, a brush, and paint and told them to paint watever they wanted. You can also do a handout on fan dancing, fan language, or you can give them some Japanese symbols or writing to copy onto their fan.
Once they are dried they are a little difficult to open and close, but you just have to keep working it. The fans I used weren't of the best quality (but boy were they budget friendly!) and I purchased some extras in case of breakage which we did have.