Any tips on how to maintain balance while doing yoga?

I've been doing Bikram Yoga for almost a week now, and can pull off most of the maneuvers with relative ease. My limbs are quite flexible and I can bend and twist and braid them around my body as required. My only downfall is balance! I find it incredibly hard to stand on one leg without wobbling around and flailing my arms about, let alone twist myself into an asana all the while! I've tried concentrating my attention on one spot in front of me, but it's of little help. It's really quite embarrassing how bad I am at balancing, so I would love some ideas on how I can improve this aspect.