How to Handle Long Boards
The toughest solo jobs are holding up a full sheet of plywood, supporting the top row of drywall, and securing strips of siding or long boards in exactly the right position while you fasten them. Sometimes you can stick a clamp somewhere to support long boards, nail in a block directly below the work or even pound in a couple of nails to rest the two bottom corners of plywood sheathing while you fine-tune the placement and do the fastening.
Occasionally you'll need to place fasteners through finished surfaces, but don't sweat it. Nails leave relatively small, fixable holes and drywall screw holes are nearly invisible. These little insults are pretty tame compared with the mess you can have with a falling cabinet that you're trying to hold up while fastening!
Big, cumbersome cabinets are easy to hang alone if you first screw a level 1x4 through the wall into the studs at the right height. Then you can rest the cabinet while you fasten it to the wall. Holding 10-ft. gutter sections for fastening is a hassle. But support the far end with a clamp attached to the bottom of the fascia and it's painless.