The first flag I painted up for my reenactment character, the bishop, was not his banner ( his personal flag) but his standard.
This is the flag that his soldiers follow and rally to.
Hence, it would be 'trooped' before his soldiers, so that they would all know what it looked like.
The banner has the bishop's arms on it; his standard has his badges and livery colours.
The bishop's bages are the devil climbing a hill holding a pearl ( a cant- or heraldic joke- on de Velmont... devel mont, or the devil climbs) and the red mitre
His livery colours are black and white- so his soldiers would wear surcoats black on the right and white on the left with a red mitre on the left shoulder. His officers would wear the demon and hill badge instead of the mitre.
When I painted the flag, I was concerned that the devil badge would not stand out if I used the black livery colour as well as the white, so I edged the banner in black instead.
It looked like this