I've been designing games as a hobby for about four years now, and have encountered and overcome various issues regarding prototyping, but I wonder: What are the most problematic type pieces for others who are trying to make a decent prototype? I realize many bits, such as hexes, squares, or other shaped tiles can be cannibalized from existing games, but surely other solutions are used.
What are the problem pieces for other designers, and what solutions have they come up with, including cost?
Just use carbouard chits like the old AH games.