Aerosol touch-up trick
Through the center of a folded newspaper, cut a hole the size of the spot to be sprayed and center the hole over the spot, as shown right. Peak the fold slightly above the surface, and make several quick spraying passes across the hole. The moving spray prevents finish from accumulating in one spot, and the raised paper allows some of the residual spray to creep beneath the edges and feather out over the surface.
—From the WOOD magazine shop