about 24hrs. in advance and place the queen below an excluder then in the second Hive body frome the outside on both sides I put ... honey, pollen, capped brood, then in the middle I put eggs and larvae with pollen on one side and larvae on the other. I then take a bunch of nurse bees from other colonies and put them in with the eggs and larvae. The next day I graft, I pull the middle frame out with the eggs and larvae , wait about an hour and put my graft in the empty space. The nurse bees are waiting to jump on them. This has always worked great for me. The is from Queen Rearing and Bee Breeding by Harry H. Laidlaw and Robert E. Page Jr. They list a number of ways to set up cell builders and finishers. A GREAT book. Like they say, 1 question and 10 different answers from beekeepers. Do what works for you. LOL