When I hear about a new game, I usually read the first sentence or two on Wikipedia. I rule out games described as certain genres or types, like soulslike or online-only multiplayer games. Then, I check reviews on a site like Metacritic. If the critic or user reviews (doesn’t need to be both) are good enough, I add it to a list to play.
I also do this with movies and tv. Obviously, with sequels/series I know a little bit more about the games/movies/shows but I still go in as blind as possible.
I used to get some very good games out of discount bins and off the bulk used shelves. Lots of games that didn’t get the a-list treatment in advertising or were from smaller studios. You could pick up 5-6 games for $30 so it was worth the risk of buying them based solely on the cover.
When GameStop purged their 360 and PS3 titles I drove around to so many stores lol. Got so many awesome games at $1-5ish