To store a carpenter's square, nail either a 13-in. or 22-in. length of tongue-and-groove flooring to your shop wall, groove side up. Then, to hang your square, just drop one leg of the square into the groove of the flooring piece. The length depends on which leg you want to be horizontal.
Install additional attic insulation at right angles to the previous layer. You don’t have to use the same type of insulation – it’s fine to use batts or blankets over loose-fill, or vice versa. Upgrading from three inches to 12 inches can cut heating costs by 20 percent, and cooling costs by 10 percent.