Beyond avoiding Covid infections altogether, the next best way to prevent Long Covid is through vaccinations, reduced ~70% by recent reports and a meta-analysis of 24 studies (Figure)
https://www.scientificamerican.com/article/vaccination-dramatically-lowers-long-covid-risk/
Not to rain on anyone's parade but... given how it's extremely difficult to often even quantify and/or define what Long Covid even IS, and given the fact that even if you do not develop this particular set of long term symptoms after a Covid infection, you may still get underlying organ damage which is invisible/unnoticeable even without LC, i would tend to say the utmost caution towards infection is still in order. Also, a lot of people have underlying issues even *before* getting Covid, and the infection can and does often easily exacerbate these issues, even when you would not formally classify it as "Long Covid" afterwards.
Eric Topol
GreySkies