I am going to the board, for Sergeant (E-5), soon. I am wondering what makes a great NCO?

Take care of your Soldiers in both the good and bad. Sometimes that means doing things they won't like, but more often than not they will appreciate you.
Pay attention to NCOs you respect and try to emulate their good qualities and avoid their bad.
Always be learning for both yourself and for skills to pass down. Never be afraid to admit to your Soldier you don't know something, but know where to find the answers and get them the info in a timely manner. Nobody knows it all. BSing will just make you look like a jackass.
Communicate information from above accurately and quickly.
Shield your Soldiers from as much BS as you can.
Finally, take care of your Soldiers (repetition for emphasis).

Learn the difference between "a Leader" and "Leadership". The former doesn't necessarily have the latter. But the former can certainly develop the latter.

Dedication to your craft (MOS), be technically proficient. Learn and understand how to navigate the system so you can take care of your Soldiers. Master effective counseling, writing awards, planning effective training, advocating for your Soldiers to the NCO Support channel and Chain of Command. Being a new NCO (Sergeant/E-5) is still an apprenticeship. You’ll still be learning how to be an NCO. Putting on stripes doesn’t mean you’ve arrived and your done learning. Strive to master your profession and never stop trying to become a better NCO, Leader, and Soldier. ALWAYS set the right example. Show you Soldiers what right looks like by being the example. Good luck.

Read TC 7-22.2. Read the charge of the NCO. Great NCOs set the right example, enforce standards, are great at training troops on MOS and warrior tasks and drills, they are willing to take on more responsibility.

For your MOS, I a big failure I’ve seen from NCO’s that caused them to be disliked by their Soldiers was expecting them to do everything because they are an “NCO” and should lead instead of doing the work. As a 92A, when it gets busy, be the one who’s working the hardest. Always show your Soldiers that not only are NCO’s not “above doing the hard work,” but that NCO’s do the hard work faster and better. Show your guys that hard work makes a great NCO as well as “leading from the front.”

Respect your soldiers it seem small but it goes a long way. Even though you are their direct leadership remember you are there for them. Don't tell them to do something you wouldn't do. Lead by example, you can't expect behavior and mannerisms from them that you are not exhibiting. Also remember you're not perfect no one is, I've messed up a time or two, as long as you take accountability for your actions and learn from them.

A great NCO inspires his troops to be the best they can be. Allows their talent to shine.

A good NCO leads by example, he or she will not ask those under them to do things that they themselves will not do.

Be true to yourself and to your troops. Don’t compromise the rules. Be fair to all

I would hope you know the answer by the time you reach E4. What are the traits of the good NCO you have come I. Contact with?Honestly empathy self reflection