I'm snowed in so any last minute shopping for Christmas is completely out of the question. Fortunately I had just stocked up on magnet sheets and tiles. I didn't have much experience with stamping on tiles so I decided to read the splitcoast threads on the best technique. Two hours of reading later all I learned was that everybody has their own best way to do it. I decided to sacrifice a few tiles and try several different inks, sealers, chalks, heat set vs. non heat set, etc. to see what worked best for me. I had started with 3 different tiles, smooth 2x2, medium grit 2x2, and standard 4x4 tumbled tiles. 2x2 tiles are sold at Lowes, you get 36 for about $4. Without a doubt, staz-on ink won out and with staz-on and sharpies, I did not need to heat set or use sealer. If you use chalk you get a nice watercolor look but then you MUST use a sealer, and on the smooth tiles, you need several layers of sealer which was simply too much work for me. So here's what I ended up with. The first was a set of 4 smooth tiles, done with staz-on and sharpies, one for each season.
The second was a medium rough 2x2 just stamped with staz-on. I've cut magnet sheet to go on the back and then made little 3x3 boxes to give them in (.cut file for box can be found about 5 posts back).
Two things I found really useful that I want to pass on, 1: nail polish remover will take off the staz-on and sharpies if you stamp in error. 2: Regardless of the tile texture, a light sanding and cleaning will dramatically improve the way the ink sticks.