Use the tools in this order
Start with the seashell tracker during your first map sweep, then move to the badge tracker once the obvious pickups are done. This keeps collection checks separate from action checks, which is important when the campsite is crowded.
Use the marshmallow trainer before you return to the fire, then use the accessory previewer before spending shells in the shop. The tools are small on purpose: each one answers one stuck point and then sends you back to the game.