At our 4th Kwad Camp I did a quick overview of one my favorite maneuvers, power looping so that you fly backwards through a gap. Essentially I work my way up to being comfortable with the obstacle and practicing timing going through the gap different ways so that when I go to loop back through it I know what to expect from the gap and how to time it.
After doing this with lots of gaps and obstacles, you'll begin to be able to do it without so much warm up and practice maneuvers by having more of a feeling of how to do it for an obstacle of a given size.
Thanks to everyone who came out to our Kwad Camp hosted by GetFPV!