I graft in the afternoon in the shade. 70 degrees will not dry them out like a 90 degree day. I usually graft with a flattened out paperclip, polished with an emory board. I usually dip it in alcohol, and clean it off with clean water. I like to put mu cups in the hive for a day for polishing and scent purposes. After that, I usually graft the smallest larvae I can see with magnifying glasses. I don't prime, but it probably would help getting the larva off the tool. Feeding the hive before hand sure helps that though. I prefer "clean" grafts, meaning the larva didn't roll around, and no foriegn matter ended up with the graft. If the starter box is setup properly, and loaded with bees, they take with decent results. I check on them the next day, because I want to know where I stand as far as takes. After, I'll check in 3 days, and then you have a really good idea as to where you stand.
Double grafting to me, is getting alot of royal jelly. Do not use royal jelly from an older larva though, because it is not the same. They make it a crude mixture for workers. I do not double graft, but I still feel the key to grafting is tons of practice! Once you do it a few hundred times, it gets a little easier! But don't let anything discourage you from trying. It is one of the coolest things about beekeeping.
Dale Richards<br />Dal-Col Apiaries<br />