Are there lifestyle changes that really make getting rhinitis less likely?

Not really. If you are genetically predisposed to allergic rhinitis, reducing your exposure to common allergens might help, but the catch-22 is that you won't know which allergens you will react to until you start developing signs of allergic rhinitis. Irritant rhinitis can improve by limiting exposure to irritants such as perfumes and chemicals in your environment; avoid infectious rhinitis with good hygiene.
Yes. Most rhinitis is related to allergy (and sometimes colds). So an allergy friendly environment is very important - especially in the bedroom where people spend about 8 hours a day in there most "allergically" vulnerable state. So - cover mattress box spring and pillow with special encasings, no rugs, keep pets out of that room and windows closed during pollen season.