Great suggestions! We have run into this before and the kids usually pop out the inner part of the lid and swap them, so one has a blue ring with a green center and the other has a green center with blue ring etc. Works best for us - though next time we have the DDP I might try the carabiners!
Dreams Unlimited Travel is committed to providing you with the very best vacation planning experience possible. Our Vacation Planners are experts and will share their honest advice to help you have a magical vacation.