Sounds obvious and it should be - think of the Government swine flu advertisements where you see how easily germs are transferred and how long germs linker.  Hand washing is the single most important step in preventing the spread of germs leading to disease and infections.   We all use our hands much more frequently than we realise.

Wash your hands thoroughly and use your hygiene sanitiser throughout the day.  Make sure you sanitise your hands in front of your client immediately before your start work.  Remember that if you hands have germs on them, you will transfer them to your tools.