What is the easiest way to apply edible pearls to buttercream? Can I do it in advance or do I have to wait until I deliver the cake? It's a three-tiered wedding cake.

Thanks in advance

I use tweezers, and I do it in advance.

Do them in advance but take some extras with you just in case a few fall off. If you let the frosting crust then put them on with a tiny dab of bc.

Yeah, just stick them on while the bc is soft.