This kit comes with flag poles, but you’re left to your devices for flags. I don’t have a lot of experience with it, but I decided to try cutting aluminum from a soda can. I botched the first one when folding over the pole. The sharp bend snapped the aluminum. For the next one, I rolled it around a toothpick to give it a nice curve.
Since I’m too intimidated to freehand, I raided my decal bin for details to add. If I remember, this blue flame came from an Eldar vehicle sheet.