I usually spend an hour adjusting the terrain before even starting a city. I don't like flat land! I'll make a mountain for rich assholes to live on, and make some kind of park on top that I'll spend awhile detailing, so my citizens can sit in a nice park and see a great view all around the city. I also like making a big nature reserve with lots of hiking trails and interesting things to see.
I always try and make my city as bike- and public transit-friendly as possible, I make footpaths and bike lane bridges across bodies of water that the cars have to drive around :). I like building universities too.
Oh and sometimes I'll make an entire city block private with only one house, surrounded by trees, with their own fountain and tennis court or something. I wait until a nice house pops up and then make it historical and let them enjoy their little paradise for awhile. And then I launch an asteroid on them. It makes me feel better about being poor in real life.