I just connect to bluetooth and let my liked on Spotify do its thing. So basically every song I can think of that I like ends up in that playlist. I try not to skip anything, but occasionally something does come up that I feel I need to skip, especially when it's super slow because then I drive slower.
Sometimes, though, I get into specific moods and decide to play something else. My go-to is the Mario Kart 8 Deluxe OST because that music was literally all made with driving fast in mind so it is well-suited for highway driving. I also have a general video game music playlist that I listen to.
If I happen to be watching a really long and interesting YouTube video that hasn't ended before I have to go, then I'll play it in the car so I can continue listening, but I generally prefer to just play music.