It's really not that hard, just start the way you mean to continue. My children went to McDonalds twice in their youth, once for a party and once on a road trip

It's really not that hard, just start the way you mean to continue. My children went to McDonalds twice in their youth, once for a party and once on a road trip with no other options. We would take them to the cinema and walk right past the food and drinks. Whilst other parents took their kids to the sweet shop after school we went right to the park. There were no complaints because they didn't know any different. Clearly a lot of parents don't do this sort of thing but that doesn't make it impossible. We were far from alone.