@Adele88
we can host up to 8 guests at the same time. It's a lot of towels (up to 24) and we used to count them after check out but we don't bother anymore. We have white Ikea towels (not the cheapest but close) so our guests are not tempted to steal them. Those towels last for max 2 years when they become "hard" and not fluffy anymore so we have to replace them anyway.
My advice would be to buy nonexpensive white towels, the type you will be able to buy/restock later. Don't buy sets with some pattern because you will not be able to find the same towels if one from the set gets missing or ruined.
If you are close to the beach then @Sarah977 gave you great advice about some beach towels.
I would also advise leaving some cloth and sponges (like used dish sponges) somewhere under the sink so your guests can use them to wipe the floor, shoes, luggage and other dirty items. It will save your kitchen towels from disappearing.
If your missing towel was new and expensive then of course you can use resolution center and file a damage claim, othervise it is just not worth it.