1. Above all and most important: wear a mask. Reuse it for two weeks. Disinfect it with alcohol.
2. Keep your mouth shut. Breathe through your nose (infections are worse/more likely if they enter via the mouth).
4. If you have hayfever: double your efforts to clear it as it can make your nose stuffy and make you a mouth breather.
6. Don't drink. Alcohol makes you lower your guard, talk loudly to people (spit flies further) and take risks. Save the alcohol to rub on doorhandles.
//End.