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.
A measuring or rafter square is a great addition to any tool box. You can use it to mark a board for square or angled cuts. It fits securely into a tool belt and can be used to check the trueness of an angle or as a cutting guide for a circular saw. It's also handy when you're working with large-dimensional lumber or when you're laying out rafters.
After a few uses, resin will build up on your drill and router bits and lessen their effectiveness. An easy way to clean them is to slip on a pair of rubber gloves and safety goggles then spray each bit with household oven cleaner. Scrub away the resin with a medium bristle toothbrush. Rinse and thoroughly dry each bit.
If you'd like your project to turn out as strong, solid, and lasting as if a professional woodworker built it, do what they do...use your tri-square to check for squareness after each cross cut. Edges on boards that will be edge-joined must be absolutely square, so carefully check all sides. If a cut is not exactly square, use a block plane to trim. It takes a little extra time, but the improved results will be well worth it.
If you don't yet have a sawdust collection system set up in your workshop, an intermediate step is to use plastic trash bags under a tablesaw. Clip the bag below the tablesaw with snap clothespins. The sawdust that does not fall in can be scooped up and tossed into the bag. Also check out the options now available for using your wet/dry vac to collect sawdust from individual tools.
If you are making up sliding jigs for the tablesaw or other tools, consider steel rather than wood for the guide runners. Steel runners won't swell like wood will during high humidity to cause sticking and binding. You can ask local steel suppliers for cold rolled steel to fit the grooves, or use runners from dismantled miter gauges. Steel takes a little more effort to mount, but will provide years of hassle-free service.
When using hand files, it is best to hold the stock firmly in a vise or clamp. For better results, try to keep the stock being filed at about elbow height. For heavier filing work, the stock should be lower; if the work is finer, try to keep it up closer to eye level.
To keep sanpaper discs from curling up, make a simple jig to keep them flat. Cut out two pieces of 1/4-in. plywood that are slightly larger than the discs. Drill a 1/4-in. hole through the center of each of the pieces. Insert a bolt through one piece, lay the discs on it, and follow up with the second piece. Fasten the stack with a 1/4-in. bolt and wingnut.
Never use the wrong type of blade in your circular saw. Always match the type and rpm rating of blade to the material being cut.
If any of your woodworking tools seem to be losing their zip, make sure they aren't suffering from surface drag instead of a dull blade. Rubbing a thin coat of paste wax or paraffin on the top surfaces of tools like tablesaws, planers or jointers, or onto the sole plates of portable tools like circular saws, sabersaws or even hand planes, can make a big difference in how they perform.