I unclip (SPDs) when my right foot is at 12 o'clock--more stable and keeps chain grease off your socks. I stood in my garage for a few hours and practiced getting each foot into and out of the pedals.

The other thing you might consider doing is, depending on your pedals, try a ride in one regular shoe and one bike shoe. The foot your bike shoe should be on is the one that you plan to put down. That way, you get used to clipping in and out, but you have the other foot if you need it, with no danger of clipping in.

Yes, it takes some practice. I was really nervous about my first few clipless rides. It will eventually become second nature.