Yep. Scan or download a flag from the internet. The bigger the better.
Save it on your computer as a jpg file.
Go to your photo editing software, even an economy type will do. Open the flag file and make a mirror image of it and save that. Copy the mirror image and paste it next to the original. Save again.
Now, open your word processor and import the file as you would clip art.
Grab one of the corner markers and resize it to the size you need.
Copy the image and paste several into the document.
Click File then Print. (Don't use the print icon.)
Open your printer properties and choose the highest resolution.
Print this on plain white paper.
Let the inks dry thouroughly.
Apply a layer of MicroScale Decal Film on the image and let this dry.
Carefully cut the flag using a #11 and a striaght edge.
Fold it at the center line and get a good crease.
Coat the unprinted side with thinned white glue. Allow this to set for a moment while the paper absorbs some of hte moisture
Again, being very careful, fold it closed. If the flag you have in mind is slid over a pole rather than tied to it, place the pole at the crease before folding the flag closed.
Care must be taken because it will be nigh impossible to strighten out once the glue surfaces touch. Now you know why I said print several.
The paper should be quite soft and pliable now. Bend in some realistic folds and furls and set it aside to dry. If you're making an air recognition banner, lay it over the kit where you want it to get it to drape naturally.
When the glue has cured, you will have a flag that looks like its in a breeze or being waved.
The beuaty of this is there is virtually no cost and you can find just about ent flag on the internet.
You can use this same process to create airborne flag patches, unit patches, rank chevrons, blood chits or nose art for the back of flight jackets in just about any scale. You could even do modern name partches. I did a blood chit on a 1/35 scale pilot coat and could make out the Chinese characters clearly under a magnifying glass. Apply these to the model with thinned white glue and carefully press them into the folds. Seal with your preferred flat coat.