I found this worked best for me, I'm on Ubuntu 14.04 LTS
First, create a blank file on the desktop, name it Terminal.desktop (or anything-you-want.desktop)
Open the file with your preferred text editor (gedit, vim, nano, etc.) and paste/type-out the following:
Comment=Terminal Desktop Shortcut
Save and quit.
I know I know, the icon doesn't look right yet, don't worry! Right click the file, select Properties, go to the Permissions tab, and tick 'Allow executing file as program'.
Alternatively, you can use
chmod 775 Terminal.desktop
chmod +x Terminal.desktop to give it execute permissions
using the terminal if you prefer terminal commands (when you are in
N' ta-da! That's all, really simple, looks pretty and works well too :)