For those that don't have access to diapers or can't risk wearing them cos of parents etc and like being padded:
Something I have always liked to do (In bed) is to wear trackies/poo pants/whatever you call them and shove T-Shirt/s or any other soft material clothing down into the crotch. Try lying on your side, front and/or back. Such a nice feeling (I guess nothing beats wetting diapers but that can get a bit costly!!) and cheap (all you need is the stuffing and the pants)
Anyone else ever tried this??
I think I have enjoyed doing this since I was around 10.