The secret sauce is steam refunds. If you buy a game through the steam store and play for less than hours you can get a refund within 2 weeks of purchase. A bot will auto accept the refund. The humans who review other refunds are also very flexible and I've had some refunded for various reasons.

I would take note of games I actually enjoyed and figure out what will get me a similar experience. The generals on /vg/ can actually be useful for this. E.g. I enjoyed Baldur's Gate 3 so I found the CRPG general and looked through the anchored links and asked around in the thread. Found out about Vampire The Masquerade: Bloodlines and loved that one too.

Final advice is don't buy a game just because it's on a good sale. The sale will likely affect the key price on key sites, so you can usually pick it for not too much more in the future. Only buy it if you're gonna commit to playing it. (It's usually in your wishlist because you never feel like actually playing it. Keep that wishlist up to date and realistic, it's too tempting.)

watch a video of the game before you buy it
don't buy games you won't play before the next sale