1. Use instructions from this link: http://xmodulo.com/2013/11/create-desktop-shortcut-launcher-linux.html (or google linux+desktop+shortcut)
2. In the “command” field put the correct path to your “bitcoin-qt” file, i.e. “/home/user/bitcoin-0.9.1-linux/bin/64/bitcoin-qt” (without quotes) for example.
3. Uncheck “run in terminal” and check “is executable”, if those checkboxes exist.
4. Use new shortcut (or launcher).