Yes I love to decorate the roof over my porch and I want to decorate the 2nd story roof as well. I put some small posed 33" budget buckies, a scary doll that looks like Regan from the exorcist and a black cat/vulture up on the roof too. I also have a ghoul that looks like he is coming out of the window. I attach my buckies to the shutters so they dont blow off from the wind. I can also attach them using sturdy twine/string and put the end of it in the closed window. That is also how I keep my home made prop guy from falling off the porch as well. Hes great and can be posed/dressed many ways. His costume/pose is changed every yr. Well worth the effort to make him. I also use him at Xmas time dressed up as the grinch. He is a huge hit in the neighborhood. I have him tangled up in Xmas lites.
I also use the plastic window Silhouettes of Jason,Freddie and some saying up on 2nd story windows to complete the look. I dont have pics of those unfortunatly.
You can also stick some home made ghosties up there as well as stuffed body parts, home made dead guy laying on the roof. Add some punkins too. Real or fake. You can also use halloween lites up there too, either hanging off the house, or draped across the roof for special effect or to light a specific prop. You can also add a big spider and cob web or some of the stretchy webbing too.
I also have a fragile skeleton that can blow over in the wind and break. For 2 yrs I stuck him in an upstairs window and just put a light on in the room behind him. All you could see from the street was an outline of something scary looking out the window.
I really really want to make a witch and put her up on the top roof. Ive seen someone who took an outline of a witch cut out on a board, and then back lit it so she looked like she was flying thru the sky. Really cool effect.
I love to decorate my roofs, it helps w/the whole haunted house theme. Dont forget 2nd floor windows to help w/look. Hope that helps.