After just being promoted to E-6, what advice do you have on how to prep myself for making E-7?

In two to three years....unlikely. Expect it to be 3-4 years from now. Time in grade requirements, non-waivable for selection to SFC is 36 months as SSG (per AR 600-8-19). I applaud your enthusiasm but right now, you should slow down as you have some work to do beforehand.

The SFC boards are centralized. That means that DA looks at your jacket. So, you need to look at your ERB and see what is missing and what is incorrect. Get all of those supporting documents to fix the errors and plug the holes, submit them to your Admin. You will also need to get a DA Photo. Depending on how many new awards you get between now and when you get looked at, you may need to retake that photo a time or two.

Based on STEP, you will need to complete your DLC 3 before you can even be boarded. So, get with your Training NCO and get that course enrolled and completed ASAP.

After that, then you need to be boarded. Keep an eye out on the HRC website as they constantly update when the boards convene and what the ranges are for who will be looked at. If you are eligible to be boarded but won't be boarded, your name will appear on the RED Report. This is a spreadsheet of all eligible SSGs with issues that need to be corrected before they can be boarded.

Once boarded and selected, then you have to complete your SLC phases. For your MOS, I don't know how many phases you will have...I know medical (68 series) has two phases. You will need to complete all of your SLC phases. Naturally, this will depend on seat availability.

My first recommendation: do not make your career about promotion, and don’t communicate that your main desires are promotion. That’s a bit how this post reads.

Your profile says your goal is to be a green beret? Hurry up and go to selection. 18 series compete by having time on an ODA. The longer you wait to go, the faster your potential peers will get promoted around you.

If you don’t go SF, then just focus on being the master of your craft. Low density MOSs have the opportunity to absolutely shine, or be a grease stain. Volunteer for additional duties. If you’re airborne, go jump master. Keep your PT high. Excel beyond your peers. Keep going to college, even just a few classes a year to show continued progression. Keep your NCOER support form tight. Keep your records tight from now on. Don’t wait until your SFC board profile opens to “clean up your records”.

Continuously seek a slot at SLC by working with whoever the POC for your schoolhouse is to obtain a slot, sometimes those who are scheduled defer for various reasons. Seek mentor ship in various subjects from senior NCOs

There’s a bunch of info on the HRC Enlisted promotions page on the senior enlisted promotion system. I suggest you read up on that and look up the HRC videos explaining the promotion board process for how the board rates packets. It’s a good half hour class at least and way too much to explain here