White wash one side of the houses with watered down white craft paint.
Once they have dried hot glue a reed/skewer/stick to each side of the back of each house.
Trim the sticks to about 1 inch below the bottom of the house.
Wrap the branches from the wreath around the bottoms of the sticks.
Wrap branches and/or hot glue the large trees behind the back of the center of the houses on the bottom.
Wrap branches around and/or hot glue the other bottle brushes around and between the houses.
Add a decorative bow at the top if desired.
Hang and check for spots where you may need to add some hot glue to firmly secure the houses or trees.
Notes
You can find smaller blocks at the dollar tree. They should work though you may need to adjust the size of the numbers to fit or make your own.I reused an old wreath and bottle brush trees from other projects but you can easily find them at Walmart, Hobby Lobby, or Michaels.You can leave the houses in their natural wood state instead of white-washing them. Or you could stain or paint them in any color you wish.