Everything is segmented in layers, so just pick the color division (full, vertical split, horizontal split, 4-way, checkered) and various bits for the banner (wreaths, flowers, pleters, heraldic symbols). Drag, re-scale and change hue as necessary. Save as PNG.

Final step is to re-size your new banner to 132x340 (the initial file I worked with from another tutorial was the wrong size) and place it into one of the banner files, save as dds (1x alpha) and enjoy your banners