How can i avoid frequent sinus infections?

Difficult: Other than frequent hand-washing to prevent the spread of viruses and bacteria and avoiding sick contacts, there isn't a lot more you can do. Certainly controlling nasal allergies can help, with the use of nasal sprays and other meds. Saline irrigation may help.

Limit exposures: Several things contribute to chronic sinus problems. Most issues are not truly infections, but usually more congestion. Avoid smoking and smoke exposure, explore allergies, consider nasal saline irrigation, and avoiding dairy products for 2 weeks (most adults have some version of milk allergy).Sometimes, recurrent issues can be from lacking some immunologic factors(iga, etc) may help identify.