I have been working on making this instinctual as well and here are some things that helped me.
here are some things to practice
first off use the cross boof to boof from peaks of waves and over holes that are insignificant, and pf any small ledges you can find
secondly remember that comfort on the off side with the boof is related to you general performance on that side, so strengthen your off side in general here are some lines to look for:
-find boofs that are onside and land in an eddy, while air-born cross the bow and land doing a cross draw to finnish the eddy turn (this helps with balance too) so righties thats a left eddy turn. This is also the motion you will use when you do an off side boof and then transition back to your off side.
- Use the off side high brace: do it while side surfing, or more aggressively fall into holes and of ledges sideways off side first
As for the body position, remember to lead with your head. So you are a righty going for a boof to the left into an eddy (Sunshine on the narrows is a well know example of this), reaching across the boat for the boot, scraping of the rock etc is tilting your boat left and you are going to want to land neutral or tilted right. there is nothing you can do about this until you release, then you want to roll your boat as you fall. To do this drastically reach to the right with your head, once you finish the boof and release your hips will have no choice but to follow you head and roll the boat. this works on the onside to.
look here
it is easy to see eli do on this on side boof at 1:44http://
www.youtube.com/watch?v=EDjiO2hKeiw
sorry its not an off side boof but look around and watch the paddlers head.