I've already done 3, but I need to take some more pics of them. For now, here's what I have.
This one is a P-40 with Flying Tigers markings. The model is a Revell/Monogram P-40 with a few slight modifications. I wanted reasonable historical accuracy without getting too fanatical about it.

The Flying Tigers used P-40s that were built by the U.S. but were provided by the United Kingdom, so they are sporting UK camouflage colors and the sharp transition between colors. The camo is deliberately a bit sloppy to give the impression of being maintained under field conditions. I added the antenna wire from each wingtip to the tail. The markings on the wings are the Chinese roundel from before the Communist takeover that happened later.
I know it's a horrible picture, but I'll put up some better ones.
Next, I did a Supermarine Spitfire MKI, as used by the United Kingdom in the Battle of Britain. This image is NOT the completed model. The kit is the Airfix Spitfire MkI.

The messy part around the UK roundel on the wing is from decal medium, which I absolutely recommend you use on your own models. It softens the decal, making it fit snugly over surface details like rivets and panel lines. Then, after all is dry, you h it it with a coat of matte finish and it looks like the decal was painted on. Again, British plane, British colors and sloppy, like a plane that has had the paint touched up a few times.
The third was Accurate Miniatures' Yak-1 fighter, as flown by Lilia Litvyak.

The Soviet camo had the softer edges so I used an airbrush to do the pattern. First the plane was painted all green then the black was airbrushed on. The canopy is masked using simple white glue brushed on and after the paint dried it was removed, and I think worked out decently well. This kit didn't come with a pilot so I went on eBay and got a resin 1:48 scale Soviet Yak-3 pilot. The only difference was that the seat was wrong for a Yak-1, so I cut it off and attached the seat that came with the kit. Then I tried a little sanding to make the pilot's face look more feminine (results... meh.) to represent the "White Rose of Stalingrad."
I'll take pics of the completed fighters and add those later.