Athletic tape. I've found KT tape starts to peel/fall off throughout the day, Get something that holds really firm and well. Shit that like football and hockey players use.
I had a bad ankle injury a few seasons ago (painful skiing the rest of the season but you gotta make due sometimes) and made sure to wrap my ankle/foot every single morning. Combine that with the support of your boot, assuming they fit well, and you'll be pretty stable. It doesn't completely get rid of the pain at all but you can still be able to ski. Plus if you happen to fall or tweak it again, it helps keep swelling down till you get the boot off.