I place the track where I want it, then use a sharp pencil or marking pen and trace a mark on the table top surface under the center rail between ties, using the center rail as a ruler. I only do it every 3 or 4 ties, and it goes quickly.
Then I remove the rail and line up the inside straight edge of the cork with the trace marks I made and staple the pieces in place. I have a plug in power stapler that I bought at the local home store, which was reasonably priced. I use 3/8ths inch staples. It holds the cork in place until I lay the track on top of it. Very easily removed if you want to tweak your design. I use a light hammer on any staples that are sticking up.
Mike