I've pretty much given up on reusable bags. I almost always do grocery shopping at random times, and never bring my bags with me when I leave the house.

That's why if you use a car you have more bags that you need on one run in the trunk. Then you keep bringing them in the house by twos or threes and at some point you drown in reusable bags and put them back in the trunk.

Having developed a hate for all those one use bags clogging your trash also helps. I've started doing this before it was the eco thing to do just because I hated accumulating bags.

Walking to the corner store(tm) if that option is available to you requires a bit more discipline, but I mostly remember to pick a bag when leaving home.