What I did was to sketch the map and what to put where, but while I was doing that I just flattened the area as much as I could so that when I had a clear picture of what I wanted then I could build straight away. Once I knew what I wanted I planned very building before I built it.

 

Have some cash for investment if your looking to create prebuilds. I also highly recommend you do invest in quality building materials, it increases your town value and plot values if the town is designed well.

I didnt draw a visual plan for my town, although I have a image of my main town areas which I can build from. Once my towns complete I'm going to try create a 3D map, if that hints any ideas for you.

You may already know that there is a metric ton of towns around, make sure yours is special and above the rest in some way. If it's a residential town where people live, create attractive spaces and buildings. Maybe avoid flattening your town completely, make a flowing landscape. Flat towns look boring and unattractive most of the time, even if it involves sacraficing a few plots.

Include features that towns folk can use/do whilst in your town. Parks, Rides, Farms, Cooking Pots, Fishing Tables, Stores, all make your town more common to a flow of traffic. Make it a place where people can get most of their needs without having to leave your town or purchase perms from other towns.

Hope this sheds a little light for you with towns, Goodluck!

 

Keep your town organised.
I have seen ugly towns because there houses are just everywhere! no paths or anything.
Just try to keep it tidy it will make a real difference to how people view your town!