Use caster sets to keep your major tools, even workbenches, portable. Wheeled tools and benches will allow you more flexibility, and will let you reposition for specific jobs like ripping long lumber or for taking advantage of natural daylight.
Use stone instead of dirt against a retaining wall to aid in drainage.
To prevent a belt sander from tilting near the edge of a workpiece and rounding over the corner, place another board that's the same thickness up against the workpiece. This way, the sander rides across the edge and on to the abutting board instead of rounding it over.
If you have a room air conditioner, remove it for the winter or seal it up and insulate it. Water heater insulation jackets can work well for covering and insulating the air conditioner.