Originally Posted by brewer90
It is a balancing act between keeping enough weight on the back to maintain traction, enough on the front to maintain steering and moving back to unweight the front to clear obstacles and forward to get the rear over it. Stand up in a crouch to get your weight off the seat, basically stick the nose of the seat between your butt cheeks and keep your chest down over the bar. Now it is easy to move your weight front and back.
Another tip is to look past the obstacle you are about to hit. If you stay focused on it you are more likely to smack it with your front wheel or not be prepared for what is next if you do happen to clear it. Also try to pedal in circles in order to keep your torque constant so you don't have any sudden bursts of power that spin the rear or pop the front up. I avoid the granny gear too since it doesn't get you enough momentum. Finally practice riding super slow. Do track stands and just get comfortable staying clipped in when your forward progress stops or comes to a crawl. I used to bail when I would hit something that slowed me way down just based on survival instinct but once I got good at slow riding I was able to stay clipped in and clear stuff that I always used to have to walk.
I'm actually pretty comfortable keeping the bike upright at very slow speeds, or even at a full stop for a few seconds. Doing that with clipless pedals still freaks me out though, due to the fact that the last time I couldn't unclip my foot in time, I ended up breaking my hip as a result. Eggbeater pedals are very easy to get out of though, so it's just a matter of getting more practice with them until clipping in and out becomes instinctive. For some reason I have a very difficult time getting my left shoe clipped in, so if I had to put my feet down on a hill, I would definitely have to walk the bike up. In any other circumstance though, those pedals work much better for me than flats.