The nice thing about a military base on your layout is there are so many detail items you can include to add interest.
For example, in the photos I posted earlier, I removed the Lionel pennant (put it back in the box) on the LED-illuminated flag pole and added an Air Force flag under the US flag. If you look at the Quonset hut, you'll see where I put a couple of little "flower plots" outside the door to dress it up a bit (like some young enlisted person would be told to do on a base beautification detail!) (Been there, done that during my time in the Air Force.) I stole the "flower plot" idea from the Gomer Pyle show; they had the same thing outside their Quonset hut.
Here's another one -- anti-terrorism vehicular "jacks" just like you see at so many base gates. Get your ID cards out, folks, for the sentry.
Most of those jacks at real base gates are crudely fabricated out of scrap pieces of iron. They are definitely not a piece of finely made ironwork--they designed to stop vehicles! Since I couldn't find any metal jacks in the dollar stores, I used some plastic ones and cut the "round ball" knobs off them.
One idea I had a few weeks ago was to use one of the Lionel gantry cranes to raise and lower missiles out of the missile railcars, but I'm not sure yet how to make all that work right. It would certainly be an interesting use of that accessory!