Jack,
Once you're satisfied with how it starting to look, my recommendation is to burnish each tile with a plastic spoon or other such implement. This will ensure good adhesion so that tiles don't slide around as you work and also reduce the chances of tiles peeling off later. It will also smooth the tile out to eliminate any wrinkling or creasing created from handling the tiles. It should leave your nail dimples visible, but you should experiment on a test piece first: the hardness of the wood used for planking and how hard you press with the spoon will effect the outcome. I like to burnish each tile as I go along, but I don't think it has to be done that way.