Favorite position for anal? Best prep?

My husband and I have done anal several times. The problem I have is the amount of time it takes to get ready for it. I have to have my husband start with a small finger, work his way up to larger fingers, two fingers, a small toy, a plug, then finally his penis. Every time. If we don't work up gradually each time, it's painful. I'm usually too impatient and want it too bad that I try to rush it and then it ends up not happening because it hurts.

Any tips for getting there quicker? We always do it with me leaning over the bed. Anyone have other favorite positions? We did try missionary one time and I did not like it. Spooning was okay, but not great.