What do you do when a soldier refuses to listen to your directions?

You given him the golden statement: : PVT Snuffy you failed to be in the correct uniform for X formation. The prescribed uniform is blah, blah and blah. Army regulation 670-1 clearly states that sunglasses are not to be worn in formation. When informed to remove them you chose to disregard the order given you. That is a violation Article 92 of the Uniform Code of Military Justice (always spell this out, it is proper English, and has a more dramatic effect), actions of this nature can, and will result in actions under the Uniform Code of Military Justice. Furthermore this can result in discharge under less than honorable conditions, forfeiture of all veterans benefits not limited to health and education, and follow you for life. As this is your first offense I am recommending the following corrective actions: A. for the next week you will after duty hours report to me at X hour, in the following uniform, with the following uniforms available. PT summer, PT winter, Class B, Class A, Field Uniform (what ever your units field uniform is to include full battle rattle and Armor vest). Every 30 minutes you will change into a those uniforms and you will meet (at a location that makes it inconvenient but not impossible to do, flag pole, mess hall, or some other place), If for any reason you are not in the correct uniform, you will reappear at the end of the normal changes in the correct uniform. Or you may elect to see the commander for actions under UCMJ.

Be legal, but be inventive. Don't be afraid to dry different stuff, just don't go overboard.

If that doesn't work, well there is a bag of camouflage poles in the back of an LMTV, or a good session of conex counseling, but seriously, this person is challenging your authority, don't lose your cool, because that is what they want you to do. Instead show the individual you have far more inventive ways of getting them to go along with the plan. Was he late to formation revoke pass privileges for two weeks, if they live off post move them in the barracks. There are ways to get people to tow the line.

Make that soldier life a living hell and hopefully he will go AWOL.

This is a serious problem. had he refused in a private counseling session, you could have put him in front of your Platoon Sergeant, and, if necessary, the First Sergeant, to square him away and keep his record clean. Now that he has refused a lawful order in front of the unit--in formation, no less--he needs to go to NJP--and if I was his Company Commander, I would send him to the Battalion Cpommander, recommending trial by court-martial. Otherwise, the rest of the unit sees that there is no discipline in the unit and everything goes to hell.

I would like to respond to SFC post below but wish to post directly here. I totally respect the approach and philosophy of SFC with crushing the Soldier's glasses as a response to disobeying a lawful order in front of other Soldiers. This may work if done with finesse and you have a repoire with the other subordinates and the NCO Support Channel and Chain of Command has your back. If you did that though you may not be able to formally counsel him on recommending UCMJ or even corrective training. You would just be adding insult to injury in the eyes of your Soldier. The other part is that now the Soldier can go to the Army lawyer or Legal Assistance Center and put in a claim against you for the cost of replacing the Ray-Bans. That Soldier has a right as a Soldier to do that. Now the pros may outweigh the cons for the SGT if he or she is willing to fork out the $200 but still retain discipline within the ranks. I can say more on this but I will leave it at that for now.

Man, my Chief would have responded with a deafening "GET THOSE FUCKING SUNGLASSES OFF YOUR FUCKING FACE BEFORE I SHOVE THEM CLEAN UP YOUR MOTHERFUCKING ASS" and at that point I'm not sure anyone would have had the balls to continue wearing them. But if they did, I'm pretty sure it would have resulted in a write-up for Captain's Mast for insubordination.

I assume that you're Army but I'd suggest that your giving a lawful order and therefore is punishable under the UCMJ. First off you should have a Letter of Counseling and start a UIF folder, next step would be an Article 15, etc.

You document the whole incident and then write up a negative counseling statement on that soldier for insubordination and you cite the AR and UCMJ code that he violated. If it's bad enough you can even push for a company grade Article 15.

This doesn't require paperwork and feel good stuff. Take them off or walk around with an MRE box above your head yelling "I'm so bright I need shades"

Apparently this soldier needs some corrective training in following orders. I would suggest grass drills to help the soldier understand that my orders are to be followed quickly and without question. He needs to hear my voice, understand the order, and follow it smartly. You could even incorporate "remove sunglasses" into the corrective training. "Up", "Down", "Roll Left", "Remove Sunglasses", "Roll Right", "Go!" The training thus gives the soldier the opportunity to understand his mistake and correct the error.

put it on paper/extra duty