Identify pieces of scrap wood that you can use to make houses and trees. Once determined, roughly sketch the cut lines.
I found that paint sticks were the perfect width and thickness to work as roofs. Cut them to the sizes you need for the houses. Remember to leave some overhang.
Paint houses and trees in color of choice. I decided to give everything a coat of snow and painted the trees accordingly.
Attach the paint stick roofs to the houses. I used a pin nailer for this. But a good quality hot glue like this one should work as well.
Last, add icicles to the roofs using hot glue.