Install the 'gnome-panel' package through software center (also called the "launcher and docking facility for GNOME"):
sudo apt-get install gnome-panel
Open a new text file and name it 'Create Launcher'. Into the text file add the following 2 lines:
gnome-desktop-item-edit --create-new $(pwd) &
Make the text file executable by right clicking on it and in Properties choose the Permissions tab and check the Execute box. Move the 'Create Launcher' script into the ~/.gnome2/nautilus-scripts directory (which is hidden). Then right-click on the Desktop and from the pop-up menu choose Scripts > Create Launcher. A dialog very similar to the one in Gnome 2 (where the icon name, command, icon, etc. can be specified) pops up. Fill in the details as usual for a Launcher.
Desktop icons have to be enabled, if they aren't gnome-tweak-tool can fix that. They should be by default in Precise. If you can right-click the Desktop and make a folder or file then Desktop icons are enabled.