Myself, I like starting with low density suburbs-like city, then make a high-density NYC style further. I then like to arrange public transports, and finally play with the terrain to make some mountains villages, coastal city, etc. That’s usually when I just spend more time following cars or trains around my city than playing.
Oh I feel you haha, up until recently I’ve been using an i5 2500K, which showed a little bit of age. Since then I’ve upgraded to an i3 10100, so it should be a little bit better, but I haven’t played Cities with it. I plan to upgrade to something like an 11400 or better for Cities 2 :)