What are some things I can work on now to make me a better NCO when it happens?

Here is a start:
Be consistent in all things. Insist your Soldiers are consistent.
Be present; be prepared; conduct PCCs/PCIs early enough to fix what isn't right.
Train your Soldiers, and teach your Soldiers what it takes to advance and be successful.
Read and research regulations and policies, and when you give advice, ensure you provide your Soldiers the reference. Demand the same from them.
Be involved with your Soldiers. This doesn't mean you're hanging out drinking beer with them, but spend time to learn where they're from, what challenges they face, and what skills and knowledge they bring that aren't obvious.
Keep a current Leader Book; show your Soldiers how to develop one; and, insist subordinate NCOs do the same.
Counseling: Use it to develop, and complete follow up. Look for opportunities to document good events. For corrective training (which you supervise), document the standard, where the Soldier fell short, what the Soldier and you will do to correct it, and follow up as to whether it was completed successfully. Counsel on promotions BEFORE they are eligible--6 months, 3 months, and when eligible, and honestly state what your recommendation will be (you will track eligibility in your leader book)
Maintenance: check the equipment/vehicle for deficiencies listed; insist and use TMs; and get your hands dirty. Track it in your leader book.
Identify every support agency on the installation (AER, Red Cross, Education Center, etc.) and physically visit them and speak to the people who work there. Get the numbers and add them to your Leader Book.
APFT: Goal 300. Have your Soldiers set incremental goals, also.
Learn how to write awards and NCOERs. Get copies of approved awards, certificates of achievement, and NCOERs. Find opportunities to submit awards for your Soldiers.
Compete for NCOQ/Y and SAMC. Motivate and help your Soldiers do the same.

Ensure you lead by example. Score 300 on APFT if possible. Study for the asvab and raise your score if possible. Study all areas associated with your MOS making yourself an SME. Study othe MOS that are closely related and be able to draw the bridge between the two or three. Know the vehicles associated with you duties like the back of your hand. Look for a volunteer opportunity of something that is deer to you. Learn about the Army Family, Family Readiness and associates issues married or not. As an old Soldier might say, Be all you can be!!! Thank you for your service.

Being an older guy will help you. I had a 17 year break in service. I came back as an E-4 and rose up the ranks fairly quickly.

Use your age and experience (whether civilian or military) to help you make decisions. Use what life has taught you to your advantage. Don’t be afraid to use your experience outside of the military to help mold you into being a leader.

Remember all the leaders you worked for in the past. Figure what you liked and disliked about them. Copy the traits of the ones you liked and remember the actions of those you disliked. What did they do that you hated? Don’t repeat those actions.

Just remember, it’s all about troops. If you take care of the troops, they will take care of you and the mission.

Good luck