It if helps, I unclip if I even Think I'm going to have to stop. I figure if I don't stop - I can always clip back in but this way I'm "ready for anything". I also just rode around my neighbourhood while clipping and unclipping without worrying about stopping until I got used to the "action". I also practiced riding unclipped with my feet on the pedals so I could get used to that feel. In my case I ride a bike path but it crosses major streets plus a school street so riding to work can get very interesting some mornings! Good luck with your pedals - I LOVE my clipless and was sorry I waited 6 weeks to get them!
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"