The reason I have put up this page is because banners in Minecraft look awesome if you make them in a certain way that you like. To design your own banner, you can use THIS LINK to create and design your own banner that you can design and edit to get ready to make them on your Minecraft world. I have a few example banners that I think look pretty cool.
Top 10 Banner Designs in Minecraft by Eystreem
How to Use the Loom by OMGCraft