Hi DJC
If you take on any new work in the future, do what I do, I give a price for the windows, and then say for another £2 or £3 (you decide) you'll do the frames, first time is a losser for me, because there usually filthy, but after that a quike wipe,and your making extra money, and 9 out of 10 times the customer goes for the frame's included price.
As for Guttering this all depends on your area and would best be helped from someone nearer to you, But as a rule were I am, on a normal three bed semi, I charge £25 for front and £25 for the back, and a bit extra for extra guttering, like a garage that is joined to the house or if they want the guttering around any other building that is joined to the house.
You can make a lot of extra money through out the year, Taking on the extra work.