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

How about? "Hey man?" or ma'am. "I don't know how to address you but could you help me?

As an E-4 in the Army to an E-7 would be Sergeant. To an E-8 Master Sergeant it would be Master Sergeant, to a First Sergeant it would be First Sergeant. To an E-9 it would be either Sergeant Major or Command Sergeant Major as appropriate. They are never addressed by their first names. Show respect where respect or due!

In the Army, in all seriousness, all NCO's, E-5 to E-7 are referred to as Sergeant, with E-8 1SGs referred to as First Sergeant or "Top", if they are ok with that, most are, and E-8 MSGs rendered to as Master Sergeant, though, often, you can get away with referring to a MSG as Sergeant, though it's respectful to add the "Master". Any Army E-9 is referred to as Sergeant Major. Period. End of story. Don't get that wrong.

Marine NCOs are referred to by full rank, i.e, Staff Sergeant. As stated above, you can call an E-7 Gunny, most of the time, or an E-8 Master Gunnery Sergeant, Master Guns, and an E-9 is Sergeant Major.

Navy E-5/E-6 are usually rendered to as Petty Officer, E-7 is Chief, E-8 is Senior Chief, and E-9 is Master Chief(with delusions of HALO, LOL).

Air Force, E-5 and E-6 are reffered to as Sergeant, E-7 is referred to as Master Sergeant, E-8 is reffered to as Senior, and E-9 is Chief.

Disclaimer: I'm an Army NCO, who spent a lot of time in JSOC, so if I have made any errors, please let me know, but I tried to be very diligent, in learning how to address fellow NCOs, from other branches, and that is how it was taught to me, I'm a Ranger, but I'm not COMPLETELY perfect, Lololol.

While in boot camp, just about everyone is a sir or ma'am. I was in the USCG and our ranks are the same as the Navy. E-4 through E-6 are petty officers. E-7 is a chief, E-8 is senior chief, and E-9 is master chief. Do not and I repeat do not call a Chief petty officer , Senior Chief, or Master Chief "sir". They work for a living.

Sgt . Always worked for me . As for my thoughts on others . If I did not know you , I called you by your rank

Enlisted in the Navy typically refer to each other by first name regardless of rate in informal, professional settings. When someone becomes a Chief Petty Officer, their first name is officially changed to “Chief!”

It's been my experience that you're never wrong in the Air Force with using the rank. Having said that, for E-1 through E-4, Airman works, for E-5 through E-7, Sergeant works, for E-8, Senior is now an authorized form of address, and for E-9, there's Chief. Also, unlike in other branches, I see "sir" or "ma'am" used regardless of rank.

Senior Thank You

Across my dealings with different branches it varies but not by much.
Marine enlisted full tank ie staff sergeant, gunnery sergeant...etc
Army enlisted E-5 to E-7 you call them Sergeant unless it’s an E-7 in artillery you call them smoke..E-8 either TOP OR FIRST SERGEANT E-9 Sergeant Major
Airforce enlisted sergeant until E-8 Master Sergeant E-9 Chief
Navy enlisted by the rank until E-5 chief petty officer is reached and you call them chief or until E-9 command master chief is reached then call them that

NEVER EVER EVER call a Navy Captain Colonel