If you are installing new shop lights or positioning a workbench in your shop, a simple test can help you find the position for best illumination. Hold a pencil or dowel vertically, then check for shadows. Reposition your set-up to reduce shadows as needed. If you have strong shadows on one or more sides, consider buying more lights.
Look for dirty spots in your insulation, which often indicate holes where air leaks into and out of your house. You can seal the holes by stapling sheets of plastic over the holes and caulking the edges of the plastic.