If you are using Ubuntu GNOME, you may want to configure advanced touchpad options as the default user interface includes only some basic touchpad settings.
Do you like changing default UI fonts on Gnome Shell? If you prefer a uniform look and feel on your desktop, then you have to follow a couple of steps to get them right.
reNIX is a beautiful Android like theme for Gnome Shell. If you installed reNIX GTK3 theme, this will nicely complement it to make your desktop look good.
Half-left has designed yet another great theme for Gnome Shell. His latest theme is based on the look of Ubuntu 12.04 Precise Pangolin and it looks really beautiful.