I used the site favicon.cc to create my image. Although you can start from scratch with just blank squares to color in, I uploaded a smallified version of the photo I snapped of the house block. The image comes up pixelated into squares and you can change the color of the squares, etc to make your image look just as you want. I saved it to my hard drive, then I went to the Blogger dashboard Layout, and at the top of the layout it says "favicon". I uploaded my favicon file from my hard drive and it worked! If I ever want to change my favicon, this one can be removed and I can make another the same way.
The house block was made for a swap, and I have bunch that sadly are yet to be put into a quilt. They were fun to make, though!