What is the proper way of dealing with Senior NCOs as a Junior Officer?

It is a right of passage. I will admit in joining the Senior NCOs in coming up with stuff for the 2LT to do, elbow grease hunts never got old.

As a Sr NCO dealing with a subordinate Officer, the direction we provide is not a direct order, but we do support your boss. I do not make the decision for what is required, but my boss just assigned it and I need information from you to support completing the request.
The other aspect is this, if as a Jr Officer you are going through something I will have some advice for you. You can choose to accept it form someone who is now considered a Subject Matter Expert in their filed, your field, or you can go it alone. Not sure it matters to me, but I can save you from a few bumps on your head, or professional embarrassment.
Here is my problem, I have been removing dictators since you were in diapers, Dec 20, 1989; I understand I am not the boss but I am a professorial and will not steer you wrong, I'm still here for a reason. I'm good at my job, and I love serving my country. You may be the future, but I still am not the past. Lets work together and make this work.

I've never had any issues with being insubordinate with anybody in the Army, whether it be junior, senior NCO's or Officers. But there are some junior officers that are very arrogant, and as a staff NCO I smile in their face, but have no respect for them as a person whatsoever. I will always respect the rank on their chest, though. I have one at work who talks to me like I'm some sort of idiot private, I can't stand it. But I also know a bunch of junior officer's who are just awesome. I'm actually about to take HIM to the side and see what his issue is with me. I would simply do the same if I was to address a senior NCO. Just make it aware that you realize their experience, but the disrespect is a NO/GO.

Its simple...let them know that as a junior officer, I'm here to learn and lead. Notice how I said learn and lead!! Most times the "so called kids" that come from college and are in charge of many lives and property are given a bad rap. While some are aloof to the whole process, some actually use what they were taught in thier ROTC programs and expand on it by great mentorship from that platoon SGT. It all depends on the NCO that will shape that junior officer. As a NCO I did the same thing, as a Officer, I still seek guidence from NCO's junior and senior, hell I look at ideas from the privates on up because everyone contributes to the success, but a leader recognizes that input from the lowest on up shows the worth of even the lowest ranking, allowing for them to break their necks for that leader because they know the leader would do the same.

What about prior service newly minted 2Lt's? Most of them are prior NCOs or SNCOs. Sometimes the background of the indivudual can hold more merit than their current grade. I have seen plenty of NCO/SNCOs look pretty bad when they tried to "mentor" a junior officer only to find out that officer has 14 years prior service and was an E-7/E-8 or sometimes even E-9 (yes, it happens) before commissioning. The ribbon rack usually spills the beans about prior service. That and the gray hair.

I realize the OP may or may not be prior service.

If a senior NCO tells you in private you are full of shit, you probably are. That is advice. But under NO circumstances should it be allowed in public in front of the troops. Tolerate no disrespect, but always be respectful. I made it a point to be especially respectful to O-1/2s when troops were around, especially when I was a W-4/5. Any SNCO who doesn't, shouldn't be a SNCO. If you can't work things out in private, rip 'em a new one on their NCOER.

Major Steven's comments are well placed... I would add a few things though. 1.) Always be mindful of the fact that you are an Officer, and your conduct reflects not only on yourself - but the military. 2.) Give consideration for your age - and ask if these NCO's are attempting to teach you something valuable... sometimes their actions my seem personal, likely because they care about you - and if they are giving you that much attention, then there may be a reason for it - perhaps they see something in you and want to help you mature as you progress to the next rank. 3.) Don't forget that some of these NCO's are likely the same age as your parents, and while you may technically outrank them - it doesn't mean that you know more than they do about the military or the nature of politics in each specific unit. 4.) If it is a case of where they are truly being disrespectful and if it is personal, then try a "soft" approach first over lunch or a beer (if you drink) at the O-Club or NCO Club, and ask if there is something that you have done to warrant such actions, and then ask if it is the intent of the NCO to help professionally develop you or hinder you professionally. 5.) If it cannot be solved using the "soft" approach, then privately advise the NCO to discontinue their behavior. 6.) If the NCO in anyway acts unprofessionally towards you in public - then immediately stop that behavior in its tracks right away, and then order the NCO to a private room or place where the troops should not have to witness such unprofessionalism - and handle the matter privately, or with a counseling statement 7.) If there is still an issue after all that - then it is personal, and in the military - if there is a gym with a boxing ring or self-defense training mats, then by all means invite the NCO to put on some gloves and headgear and bring in a referee and go at it for 5 minutes - it really usually only lasts about 2 minutes, and afterwards I can guarantee you that there are no winners or losers... just two guys who now respect each other as Soldiers and who now understand their positions in the military. If it gets to step 7, always shake hands before and after the match and then remind the NCO that the true enemies are the ones in which you both will someday fight - putting your lives in each others hands... then end the afternoon / evening with a dinner or a drink. Last but not least, remember that while respect is always given in due accord to the rank - respect and trust as individuals must be earned... so become proficient at your job and take care of your troops - and be willing to go and bat for them even if they do something wrong and NEVER let anyone of higher rank mess with your troops (they are your troops - your family) - so always protect them! You do these things, and you will be an Officer who will be Trusted by your subordinates (NCOs and troops), and Respected by your Superiors, and Admired by your peers.

Unfortunately some are like this and you do have to tread lightly. Luckily, far and away, most truly want to help you. Sometimes simply having a sit down with them can make all the difference. Explain your expectations and tell them you want their help. Often what each party perceives as hostility or entitlement is actually just a misunderstanding.

I know things in the Army are different than those in the Marine Corps. This is what any good Marine Staff NCO should expect. That 2nd Lieutenant that just joined your outfit. Hopefully has been advised to find the most senior Staff NCO that reports to him and tuck yourself in his hip pocket. There should be a relationship between officer and senior Staff NCO where officer can ask in private questions of the senior Staff NCO. The relationship should be such that the Staff NCO can ask to speak to the officer outside or where ever and explain that he may be going to make a mistake in this situation. If officer is receptive explain to him the who, how and what For the officer it's called learning. For the Staff NCO it's called leadership. I know that every situation may not have someone that the officer should "Vulcan Meld" to. But when they do the end result is an officer that's full of knowledge and good judgement.

Carefully, Sir.