So I'm a messy person. I'm also a rather absent minded person. As a result of this, I am ALWAYS looking for things, especially relating to the fish. I lose their food, I lose my water conditioner, etc. etc.
Well, one day I was at Wal-Mart and I found the perfect thing. I was looking for a small basket to put all my "every day" fish stuff in and I saw that they make small plastic baskets with suction cups on them!! They are designed for use in the shower, of course, but I just bought two and put one on each side of my tank. In one goes my fish foods and in the other goes my water change supplies. It was the perfect organizational system for me because it's always RIGHT THERE for things to come out of and return to. If you don't like the look if it on the side of your tank you could probably get it to suction to a metal stand, or if you have a background - to the back of your tank.