Sounds like many things I do as well. I do use small wastebaskets though. To help me remember to put a new bag in, I took a cue from the amusment parks. I put several bags into the bottom of the trash can before I put the bag into it. When the full bag is pulled out and tied up, the next bag is pulled up and put into place. (actually, this is my daughters job, and it helps to remind her to not walk off without replacing the bag!).
I also use the bags to hang over door knobs when Im cleaning house. As I go through each room Junk mail, napkins, candy wrappers, stray toys (shhhhh dont tell), lost cottonballs, clothing price tags that accumulate on my dresser, etc. all get tossed into the bag as I move from room to room.
I've found that the best way to store these bags until they get used is one of those tubes made from material. They have elastic at the top and the bottom of the tube and a looped handle for hanging. You stuff the bags into the top and pull them out as needed from the bottom. I have one hanging right inside my kitchen pantry and another hanging in the laundry room upstairs so we never have to go far in search of a bag.