If you inject drugs, you can protect yourself by never sharing needles or syringes. When snorting drugs, each person should use their own tube or note.
Tattooing and piercing should always be done by professionals who work in hygienic conditions.
You should avoid any contact with blood when having sex. Latex gloves are recommended for fisting. People who are HIV positive can protect themselves by using condoms when having anal or vaginal intercourse.
There is no vaccine against hepatitis C. Even if you have already had hepatitis C, you still need to continue to protect yourself. Unlike hepatitis A and B, the infection does not provide immunity. In other words, your body has no defense against being infected again.