What is the proper way to address NCOs in different branches?

An E7 in the Marine Corp is known as Gunney. In the Army they are Sergeant. The other 2 services really don't matter because 1 is the chair force, and the other has 600 sailors go out to sea and 300 couples come back. Lol no I'm just kidding as it is common practice to pick on other branches, but to be honest I really don't know about the naval ranks or too sure about the Air Force either.

Gunny, Only the Recruit use's Sir or Mam.

Rank and name always works . I loved to hear Top by my Soldiers and Officers in my unit

You can never go wrong with rank and name

No first name for an Air Force NCO, its Sergeant ! One the fills the position of 1st Sergeant is addressed as First Sergeant. An E9 is either Chief or Command Chief if He fills that position. More recently Senior has been used for Senior Master Sergeant. A first name never make the program any time I was serving and never should. That is not a proper address at all, ever and that I would make very clear to anyone that did not understand that !

Similar in the navy all petty officers are called sir and saluted in boot camp.once graduated the honorific petty officer last name is used up to E-6 E-7to 9are chief senior chief and master chief last name optional except on formal ocasions

And when you retire or get out, all of us are Brothers/Sisters. Yet referring to ones rank still shows respect.

USN
E-4 through E-6 Address as Petty Officer so and so.
E-7 is Chief
E-8 is Senior Chief
E-9 is Master Chief

Until you learning them all, the following response as worked well for me;
“Excuses me Sir/ Ma’am/ Boss (I’m from the south, and my accent proves it)/ Superior, how do I address you?”

In Bootcamp, we call everyone Sir/Ma’am. Once graduating and becoming a Marine, we call enlisted personnel by their rank.