Re: Santa "evidence" for your young-uns.
Did the cookie crumbs, and the reindeer crumbs / pieces of carrot. Also went so far as to take a couple of 2x4's and nailed them about 4 feet apart and then dragged them across the snow covered roof of the garage (cause you could see that from the bathroom window). Both of my kids, now 21 and 16 believed till their early teens.
For the tooth fairy my wife would mix a couple of different types of glitter together (so it couldn't be found in the store) and put it in a shaker container and shook it from the window sill across the floor to the bed and around the pillow. Kids woke up with "tooth fairy dust" on them.
Man I miss them being little