This script will generate basic folder structure for your Unity3D project.
Take a look at my blog post for more information about this plugin.
Simply clone this repo into your Assets/Editor/* directory.
If you don't have Editor folder - create it
When you have cloned the repository look at your Unity. There is a new option in your toolbar.
Choose Tools/Generate Project Tree and enjoy.
Feel free to adjust this tool to your needs.
To change folder structure look at GenerateFolderStructure method in CreateProjectTree class.