Thanks for the format, @Brian Boru
I will frequently look at the "just released" and "best sellers" games to see what's going on. Then I'll search those same categories by a few of my favorite tags. It's really the best way to find new games. There's no way any publication can keep up with the number of games released each week.
Of course, I scan through the articles most days and see what games they are talking about.
Decision to put on Buy List
If I like the looks of the game, I'll wander through the user reviews. For indie games, the percentage of positive reviews is generally a pretty accurate indicator of a game's quality, but I still look through the negative reviews to see what people don't like and read the top couple of positive reviews. I also look at the trailers on the Steam page, hoping to find gameplay trailers.
I never watch playthroughs or reviews on YouTube.
In the rare case where they've reviewed the game and it isn't a narrative game, I'll read the PCG review, but I don't always find them helpful.
If I really want it, I buy it. If I'm unsure, I'll put it on my wishlist and think about it some more when it goes on sale or when I get in the mood for that genre. I have, on rare occasions, bought a game simply to support the developers.