It's easier to do it on a curb, but occasionally I'll lean so I can balance on my toes. I guess that's a no-no, then.
Is there a general rule of thumb for where your seat should be? (Besides "your feet can't touch the ground.") From what everyone's saying, mine is definitely too low. If I was riding, I could probably touch the ground with the ends of my toes. How far should they be from the pavement?