To name a few:
-Knowing their radial and DME. It's a D airport, you should be ready to report it. This is the same in the US, it's no different here
-Not tying up the radio asking for a clearance. You'll get it when you get it. There's guys trying to land, trying to get taxi clearence, trying to take off, trying to do 1000 more important things.
-Use correct radio phraseology.
-Set altimeters correctly. You're in FLs down to 40 coming down and starting at 2500msl going up. If it is set correctly, say your altitude correctly. FL 80 is not the same as 8000 if the altimeter setting is really high. Which it usually is, in the afternoon. It makes me really uncomfortable if I have to enter a hold between two airplanes and one of them is saying their altitude like they already trasitioned.
-United guys are the only ones that wave back on the ramp.
These things are small by themselves, but they are still annoying. Sometimes though, it also makes the whole already strained operation fall apart. Yes, Aruba is the root of the problem.
I named a few "US jet jockies" that never cause problems. I'm picking on the others.