As in so many other cases, doing it halfway is not serving you well. Clip both feet in every single time you ride for the entire ride. When you always do something, it is not hard to remember you are doing it. Your problem is your lack of committment. Besides, falling over due to the rare inability to unclip is essentially a non-issue. It is hard to hurt yourself that way. Believe me I know.

Ride with the clip as loose as possible until you are confident. Practice unclipping from various positions on the crank circle. Also try moving the ankle both in and out. One combination of position and direction will be just right for you. Do it that way every time.

Hey, I am the clumsiest cyclist known to man...and the worst bike handler. If I can do it, you can do it.