How do I make sure one person never runs out of shots?

Set some of your shots aside for their camera. Everything you buy goes into one pot that every guest shoots from, which is usually what you want — but a few enthusiastic guests can spend a lot of it, and you might have someone in mind who you'd rather not have run dry: the cousin who actually frames a photo, or your maid of honour. On your Papic page, find their camera and type how many shots are theirs alone. Those leave the shared pot and nobody else can touch them. If they don't use them all, you can take the unused ones back at any time — just type a smaller number. And if they DO use them all, their camera doesn't stop: it carries on from the shared pot like everyone else's. So setting shots aside is a guarantee, never a limit. Cameras are free and you can make as many as you like, so there's no cost to giving several people their own.