Use sandpaper strips to target tiny areas
When you need to sand a small area without damaging the surface around it, strip-sanding is a great method. Cut a long strip of sandpaper and trap it between your finger and the offending area, and then pull the strip with your other hand. This works wonderfully when you are removing the last remnants of a drip in a finish, or a stubborn, hard-to-reach detail. Be careful: Strip-sanding is more aggressive than it seems. Start with fine sandpaper and short strokes to avoid creating a new problem. I never use anything coarser than 220-grit paper, and most often use 400-grit on drips.
—Dean Laughren, Winnipeg, Man., Canada