This reminds me of people putting colorful stuff on their luggage to make it stand out at the airport. That can work pretty well, if you can find something fairly unique and secure it to the handle or whatever.
I use a mental trick to remember where I parked. As soon as I get out of the vehicle, I look up the lane to find a feature on the storefront that lines up with that lane. It could be anything: a rack of propane tanks, a distinctive awning, a broken light, a plant, a sale poster, or an individual letter from the store’s main sign. I then imagine that object getting up and walking down the aisle and climbing into my car like an animated cartoon. I know it sounds dumb, but it really helps me remember both the lane I’m in, and how far away from the store my vehicle is.