Anal sex without a condom. Vaginal sex without a condom. Any activity which generates blood and creates tissue damage for both partners. Abstinence, masturbation, and contact with another person that does not involve semen, vaginal fluids, or blood. It means a lubricant that does not contain any oil and can be washed off with water.
Irritated tissues are even more vulnerable to infection.
Use barriers made of something other than latex, like polyurethane. A latex allergy feels like soreness or irritation in the affected area. Don't use drugs. If you can't do that, don't use needles. If you use needles, don't share them with anyone.