BF taught me in a soccer field. It was really hard at first--only managed to do it once without falling that first day. Then for a few weeks I would go down to that field occasionally to practice on my own. It only took me a couple days to figure it out, but all this time I was riding very slowly. I think it's not so hard if you start decelerating with plenty of room to spare.

Unfortunately I never got "proficient". The dismounts were by far my weakest area when racing. I would have to slow WAY down prior to the barrier so that i was comfortable dismounting. I would always get passed at the barriers And i'm sure it didn't help that i crashed in my first race by botching a dismount.

BUT! It was still awesome! And this year i'm going to practice practice practice until I can do it at speed. If fact, I may start practicing tomorrow--after all, CX season is just around the corner