You need a gelatin subbing layer on the tiles, food gelatin will do but ideally it needs a hardener like chrome alum added but thats not easy to get hold of quickly. You only need a few drops of a 10% solution.

If your local camera shops have a hardening fixer that might do the trick on it's own. For the wood get a can of clear lacquer from Halfords or similar and spray the wood to seal it, let it dry 2-3 hours the rub lightly with 600 grit Wet & Dry to roughen the surface (Halfords again).