Have a rather large collection of adjustable wrenches, c-clamps or odd-shaped screw clamps laying around the workshop? You can store them neatly side by side just by tightening up their jaws on the edge or lip of a shelf that is out of the way. They will take up very little room and will always be easy to spot and retrieve. If the ceiling joists are accessible in your shop, they also can be used for clamp-on storage.
Have your tank inspected by a septic tank professional every three to five years – more frequently if your family uses a lot of water and/or a garbage disposer. You can reduce the strain on your septic system by using less water and staggering showers, clothes washing, bathing and other heavy usage.