I put this as an answer to the ALDI thread, but maybe more of you would like to see it. I bought a cheap dog collar with a click fastener (for a dog, not the other kind), keep it in my handbag and use it to secure my bags to the supermarket trolley.
It cost me £1.
I am always conscious of my handbag but no matter how good you are it is easy to get distracted. I have seen woman leave there bags in there trolley and go back up the aisle for something they have forgot. That is a super idea. Would never have thought of that .Thanks for sharing.