What exactly can PFCs do to guarantee they will get the 6 month waiver and promotion as soon as 18 months TIS and 3 months TIG?

SPC Jesse Bisping There is nothing you can do that will "guarantee" you'll get a waiver. Waivers may not be available to your command to give. They are doled out from higher headquarters. You can be the best soldier possible: reliable, good attitude, proficient, fit. That will give you your best chance.

It works the other way though. You'll be guaranteed not to get a waiver if you are a sh!tbird, late, lazy, shamming, complaining, and generally making trouble for your NCO Channel and COC.

The Command gets a AAA117 report which shows by TIS TIG. The waivers are doled out. If a soldier needs TIS and TIG waived, that's two waivers. Otherwise the promotion is automatic unless action is taken by the command to the contrary. As a Company Commander I only remember having 1 or 2 waivers to consider each month, sometimes none. As you can see in the attached link, the waiver is "occupied" until that person hits their natural promotion point for TIS/TIG. It's fairly cut and dry on how waivers are allocated but occasionally a 1SG will get the CSM to pull one on a one time basis.

https://ssilrc.army.mil/wp-content/uploads/2018/02/AGCCC_Administer_Enlisted_Promotions_and_Selections_ELM_LP-JAN-2018.docx

There is nothing to guarantee it. Promotions and waivers are a competition. There is a limited number of waivers available to your company. If your leadership picks you, then you'll get it.

You want to get a waiver to get promoted early? Here is what you are going to need to be aware of. When you get to your unit, you could be one of several PFCs that are wanting that waiver for early advancement. So....you need to set yourself apart from them. Stay out of trouble. Bust your ass at work. Come in early, stay late. Smoke the hell out of your weapons qual and APFT. Show yourself to be dependable and to be that "go to guy." Show your CoC that you are the biggest, baddest mofo on the base and no one else but you deserves that waiver for early advancement. Good luck.