More shoes

Framing always takes ages. I get the painting in the right place after numerous attempts, scrape chunks of skin from my fingertips trying to get the back on, and then turn the frame over to view huge bits of dust or crumbs ....where do THEY come from? I check my surfaces are clean before I start. But it gets me every time....actually about six times...before I give up and go make a cup of tea and regard the whole mess on the work table with something akin to malevolence.