As the person said above, dream towns are the best way to learn how to turn your town from plain to extrodinary. But if I may give some tips;
-Putting down paths is a good place to start. You can find thousands of paths to choose from over the Internet by using QR codes, or make your own!
-Flowers are always awesome in towns, one way or another. They make the town have that nice touch of beauty. You can either just put the flowers along the paths (like I am doing) or cover the town in them.
-Public Works Projects are a great way to make the town feel more developed. Even the villagers say so! Place them generously, but place them spaces away from each other to prevent what I call "clustering," which is where there are so many PWP that it is impossible to navigate.