Gnome 2 has this excellent feature to create custom launcher from simple right click menu option. Unfortunately this ability has been removed from Gnome 3 and there is no easy GUI way to do it in both Unity and Gnome Shell.
However, there are two methods that can be used to make custom launchers in Gnome 3.
Desktop Entry Editor, as the name suggests allows us to create and edit new desktop entries and launchers. This method works in both Unity and Gnome Shell.