Layout
If you follow along with the basic structure of most towns, you should have a few features in your Lego town: roads, some type of water feature (river or lake) and zoning areas to keep commercial, residential and industrial buildings in separate parts of your town. Look at the base pieces from which you intend to build your town and decide how you want to divide them up and what sections you want to contain what parts of your town. If you want to make a town that's more rural, design winding roads with bridges leading over rivers and creeks, open areas with trees and houses that aren't very close to each other. For a more urban setting, try building tall structures close to each other and making the roads narrow, crowded and only going in one direction. If you think about how a real town is laid out, you can create a sense of realism in your Lego town plan.
Extras
Once you have a basic layout planned, start thinking about what types of extras you want to include. Do you want to put a park in the middle of your city, or perhaps a zoo or a playground? These extras can make your Lego town come alive and be truly unique. You're only limited by your imagination and the types of bricks you have in your collection. Take a look at the more eclectic and unique pieces of Lego bricks that you have. For example, if you have a pirate-themed set of Lego bricks, you could create a museum all about pirates in your Lego town, which would make it interesting, unique and educational for your children. You could involve research in this process by looking up how museums are usually laid out and what types of exhibits they have.