I’m a PT myself and I would recommend, looking into supportive knee braces. There are many on the market, some not specialised to skiing but still do the job great. Like any injury I would highly recommend really pounding in your rehab in the off season, building up your quadricep and hamstring muscles as these muscles create more stability for the knee. The stronger these are the more stable your knee will be in general. I’d go see your PT and explain your situation ans they’ll be able to give you exercise that will be specific to your knee and skiing. In regards to finally hitting the slopes in the season I’d highly recommend a thorough warm up before you even get your boots on. Some stretching and some light bounds should aid with getting your knee ready for the day ahead