I made a few lazy/newbie modifications. First off, I definitely went with square windows vs. circles. Also, I tried to use your dimensions but it never grid-ed out like yours. It was too cramped (Mine are 18 x 24 x 2) I believe. My windows are about 1.75in and 2.5 in. I did it a while ago so now I am actually forgetting--plus I am expecting, so I am a lil loopy minded
I opted for various Christmas themed window boxes instead of decorated ornaments since my windows are squared--giving the illusion of presents. I used simple silver sticker numbers and a satin spray as a finish( It was all I had laying around--prob would have preferred a high gloss. Mod podge is not my friend, My paper did not take to it at all--in its defence I have never used the stuff before, and I grabbed the matte finish kind vs gloss. So I used a combo of a glue gun and heavy duty spray adhesive--this is a god send!!! Your idea, photos, and tut were so appreciated. I had run out of Christmas gift ideas until this. Hope you and your hunny are still going strong!