I ordered one flag to test out how I liked it from Flags of War , actually I got it through Crann Tara as he stocks them for his range of figures. I didn't want to just glue then together and have this straight flat square of a flag making my paint job look bad (if flags are done right people don't notice the figures as much) so I started searching around the internet when I popped across a blog with a how to type post. It's a post back from 2009 but still applies today here is the link Wargaming in 28mm .
I had to go out and purchase a Glue Stick and once I had that in hand I was able to sit down and start trimming out the flags. I will stress how important it is to have clean hands and laying down a clean piece of paper as your work mat, as well as some patience. Once I cut out the flags and pre-folded them I used glue stick on both sides, placed it on pole then laid it down right where I had worked on placing glue on them to get a good crease around the pole while laying flat on table. I went to flip it over and to my horror glue was on the back. I was able to lick my finger and get it off with no damage but lesson learned, FIND ANOTHER CLEAN SPOT on your paper mat to do crease, not where you slopped on the glue.
[one on left was first one, the one on right is the one I let sit to long]
Well that's it for now, I hope this helps you in future if you don't already know how to do this yourself. If all turns out well, this may well be the only way I go in future for flags.