That curtain fabric trick is solid. I once made a whole wizard robe from a thick, patterned tablecloth I found for three bucks. The brocade pattern looked like real embroidery from a distance.

Ever read that thing about how pilots do a walk-around for the same reason? @lewis.barbara is right about fresh eyes... it's just too easy to miss your own blind spots.

A good infrared camera is my secret weapon. It shows cold spots behind walls where insulation failed, or heat trails from electrical issues you can't see yet. Saved me from a major mold repair by spotting a damp patch that hadn't even stained the drywall.