Many people have learned to embrace Unity after Canonical has forced it upon them without pre-installing the usual gnome shell. But lets face the truth that Unity is a failure, at least in the desktop world. Gnome 3 looks and feels very much the same as Unity and is still a headache to many new comers to the Linux world.  But there are many themes out there that can enhance the look and feel of the Gnome3 look, you can head to http://www.webupd8.org for some of the latest themes available on gnome3 as well as news on the ubuntu world.
       For some reason the people from webupd8.org, who in my opinion provide some of the best tips and tricks for linux users forgot to add instructions on how to set the themes in their post. Anyway here is my tutorial on how to set themes on your Gnome3 shell.

1)  The first tool that you need is the Gnome Tweak Tool available on the Software Center or through sudo apt-get install gnome-tweak-tool on your terminal.

2)  Now you can do a google search for gnome3 themes ( most of them will lead you to a deviantart page where the files are stored) or you can install them via the terminal.  First type or paste sudo add-apt-repository ppa:satyajit-happy/themes
sudo apt-get update on the terminal.
    You can them install themes using the command line from the link. All you need to do is to type sudo apt-get install gnome-shell-theme- and the name of the theme.


3) Now to set the them search for the gnome tweak tool from activities.( which will either show up as Advanced settings) and open the shell extensions tab and select "on" for User Theme Extension.

4) Now you can select the theme that you installed from the Shell Theme option on the 'Theme' tab.