I can still remember the first game I ever really tried to design (and I say "tried" because of course I never finished it). I spent FOREVER cutting out custom pieces out of chipboard for the first prototype. Bad idea! After I played through it and inevitably found things I needed to change, it was very hard to do so, or to even want to do so, because I had already invested so much time in that copy. Make your early prototypes and quick and simple as possible to just test the essential parts of the game.