ALWAYS unclip the same foot first... always, get in the habit of it, conciously think about which foot you will ALWAYS unclip... then it becomes locked in your muscle memory and you will begin not to have to think about it.

The second thing you do at the same time (and I got this advice here just after I joined and its the best and most often used advice I have received) is to turn you front wheel away from the foot that is going to ground. Always.

So you are coming to the lights/intersection/whatever... you

1. Unclip foot

2. Brake/slow down

3. When almost stopped, reach foot for ground and turn wheel away from foot reaching for ground.

What happens is, when you turn your front wheel away from the unclipped foot, your bike will automatically lean towards the unclipped foot.

I have not fallen when stopping since. Its fail-safe.

Practice a few times on an uncluttered stretch of road - or better, something with a soft surface if you are worried about tipping while you learn to coordinate it.

Have fun - its really useful