Obviously, it is not possible to make a fixed rule and guideline for, how to design an awesome Custom Feather Flags (read more ideas from eyeBanner). The custom design of the feather banner is the final proof of a mix of design creative skill and advertising experience of the designer who create the customization.
When it comes to how a feather flag should be customized, dogmatism is dangerous because it has proven that successful custom feather flag design have many different styles. Coincidentally, a rule that has been accepted as a gospel by many outdoor advertisers for many years was suddenly overthrown by an extremely successful outdoor advertising event with a great custom feather flag design.