During the 20's cheek products were not referred to as "blush" but as rouge. The most common shades were those in the rose/berry shade family. By 1925 orange rouge was new and quickly became everyones favorite. Rouge came in a variety of textures just as they do today. The first layer was cream or liquid, then that would be covered with a thin layer of powder followed by powdered rouge. As for placement of this rouge, it was commonly applied to the apples of the cheeks, much as it is today, but the color wasn't ever blended into the skin. The circles were very visible to the naked eye.
For my look I kept it dark yet still subtle. I incorporated the dark smokey lids with the dreamy eyed look as well. Here's my look.