Handwashing is always important to avoid contact transmission of any illness. For me the hardest thing has always been to avoid touching your face (rubbing your eyes, itching your nose etc.), when in public settings. I've had to reprogram these commonly automatic behaviors. I also avoid people that are outwardly sick (sneezing, wiping their nose, runny eyes, coughing, diaphoretic etc.) in public. I do my best to stay as far away from them as possible, when I am forced to be in the same room, by sitting at the opposite end of the table, or auditorium.

For colleagues that are obviously ill, I politely suggest that they return home, and have gone so far as to contact their direct supervisor and request that they be sent home, so as to avoid contaminating our clients (since contaminating staff has always come across as being unimportant heretofore to upper management).

I also hate it when bathrooms do not offer paper towels, and have only sick-air blowers. I work in the health care field, and our handwashing is often vastly different than what passes as cleanliness to most people. We wash our hands for at least 20 secs, using copious amounts of soap and warm water, paying particular attention to scrubbing fingers and nail beds. We shut off the faucet using a paper towel (otherwise you are simply recontaminating your hands), and dispense paper towels before the hand washing begins (for the same reason we shut off the faucet with the paper towel). We also use the same paper towel to open the door on exit - if only all bathroom doors we pull to enter and push to exit...

I also refuse to shake hands with people that appear to be ill (I tell them that I am recovering from a cold and don't want to share it with them, so as to avoid offense) - and use hand sanitizer after every hand shake.

In public I always cough into the sleeve of my elbow, carry pocket kleenex at all times should I need to sneeze (I will sneeze into my elbow if necessary to avoid spreading my germs to all those around me). What else... some may consider this obsessive, but I almost never open a public door using my hands - I will either push it open using an elbow, and grasp the handle using the side of my non-dominant hand. I'm not nearly as crazy as Monk, but I am perhaps more aware of pathogen transmission than most