Last year, I decided I would make Caleb some Scratch Off tickets. I picked three things that I thought Caleb might like (time to play an online game undisturbed, a movie or tv show of his choosing, and a back rub). I then found clip art that I thought represented the prize it stood for well, and placed them inside a grid I had made of little hearts.
When I had printed them off, I covered them with packing tape (I would have preferred to use contact paper, but I was out). I then mixed together some white school glue and some silver acrylic paint and painted it over top of the hearts. I had to do several layers to make it so that you couldn't see what was underneath. At the bottom, I told him that if he only got one of a kind, his prize was nothing. Two of a kind meant he got a small prize pertaining to the picture (e.g. he would get to pick a TV show, have a 10 minute back rub, 30 minutes uninterrupted game time). However, if he hit the Jackpot and got three of a kind, he would get a large prize pertaining to the picture (e.g. he would get to pick a movie, have a 20 minute back rub, or an hour of uninterrupted game time.)
I think I ended up making him six tickets in all and I think he even got a Jackpot on one of them! He seemed to really like this idea, and it was a good way for me to spoil him, even past Valentine's Day.