To add on to starting and stopping games at will, take some time to just organize your library of games too! I have mine sorted into several categories...

• Forever games that I'll come back to over time
• Loved games that I may come back to should the mood strike
• "Next Up" games that I want to play soon
• Games I want to play eventually
• Games I'm done with, either I played it for 10m and I wasn't interested or I finished it and got a resounding "meh"
• Zero interest games or duplicated games (ex: the original version of a game when the remastered version was given for free and is in one of those other categories, free VR versions, etc...).

It takes a lot of focus and work at first, and a LOT of flipping between the page in your library and the store page to see if you want to play a certain game. I axed stuff pretty liberally and at different points in my life, I've gone back and pruned that list of what I want to play and see if I realllllllly still wanted to play it. I also found organizing my library a bit of that kind of "mindless enjoyable" that you can just get into a flow state to go through.

Once it's done though, when a new game gets added to my Steam Library, I can immediately "triage" it into one of those categories because it's the only thing not categorized. It's taken my library of what is now almost 1300 games acquired over 15 years and given it some more structure. Of that list, today I have ~250 in some version of "want to play", ~400 in some version of played, and ALL the rest in that zero interest/duplicate category.