I would try and put two large long pieces on, and then do the overhangs after.
So I would put one long piece down the main straight part of the house, keeping it to just the main walls. Then I would do a piece along the length of the diagonal. I would play around with different types of roof. Probably going for the gabled roof, as this might be easier for where both roof pieces come together.
I would then go around and do the parts of the house that are sticking out. I would try and keep all of those fairly similar in style, so find a style that works on nearly all of them and go with that. It gives some unity to the build.
Play around with the pitch of the roof as well, keeping similar roof pieces to the same height.
Hope that might be of some help. I've been having a nightmare with a building I'm doing at the moment that has a diagonal part to it, and couldn't get a roof to fit at all. I've ended up doing a flat roof haha :D