The best advice is to get some good bowhunting videos that have lots of "actual bulls and cows" calling, and imitate them as best you can. The Primos videos show lots of actual elk making actual elk noises.
COMPLETELY IGNORE the idiotic "so called" elk sounds most "pro staff" make, especially their cow calls.
There are darned few good elk callers shown in videos. The only one I can recommend who actually sounds like an elk is fellow Idahoan Rocky Jacobsen. He's won the elk calling World Championship several times, and he does sound like an elk.
Most "expert call manufacturer pro staff" do not.
Listen to actual recordings of cows and bulls. That will show you what you need to sound like. Better yet, get in the woods and spend lots of time with elk. Then you'll really learn how to imitate them.
P.S. Be warned------once you get in close to a vocal herd, it will be hard to wipe that silly grin off your face.