This time of year we get a lot of repair calls. This will increase as winter comes on for real and the snow and ice starts doing its business of tearing up roofs and flashing that were not ready for it. Between gables, around skylights, and particularly around chimneys we find a lot of work repairing flashing and putting window seals and access hatch and door seals. I am pretty sure that the DIY and fly by night "professional" chimney sweeps are our best generators of business as they get up on roofs this time of year and scrape of the built up "soot" around the outside of chimneys that is actually the sealants used on the flashing.
The copper flashing is very popular around here and we usually use that. For the flashing and seals around skylights and access doors we often use a repurposed manufactured seal that we can custom order for different purposes. It makes for decent paying 4 hour jobs for a 2 man crew (anytime we step on a roof we have 2 people present for our own (and out insurance company's) safety procedures. But so long as they can get 2 jobs a day in they can stay busy and make decent money.