I’ve been the tooth fairy for many years at my house.

Good idea with the bedtime thing, but you risk the kid finding it before they go to sleep.

I would wait until I went to bed to do the swap.

Before bedtime, I’d have them put the tooth in a Ziploc baggie so they don’t lose it. That way, when you slide your hand under the pillow, you can just feel for the plastic and slide it out.

For easy mode, have a second bag ready with money in it and pop that in, otherwise, remove tooth, add money, under the pillow and out the door!