Cunnilingus
Cunnilingus is the act of performing oral sex on a woman. One way to make cunnilingus safer is to use a barrier to cover the womans vulva. Barriers can be dental dams, condoms slit open down one side and unrolled, or even a piece of non-microwaveable plastic wrap. But, whatever you use, just make certain not to accidentally flip it over mid-act.
Fellatio
Fellatio is the act of performing oral sex on a man. You can make fellatio safer by putting a condom on your partner after he has become physically aroused, but before ejaculation. It is possible to put a condom on someone using your mouth, but it requires practice. Fortunately, its not that difficult to find a willing volunteer or a banana.
Vaginal/Anal Sex
To make intercourse, either with a penis or with a sex toy, safer, use a condom. Male condoms are easier to use, but some people prefer female condoms for vaginal intercourse since they cover more of the surface of the vulva and as such may provide some additional protection. However, its important to be careful since it is easy to use a female condom incorrectly. Detailed instructions for using the male and female condoms can be found at the links.
Digital Sex/Fisting
Digital sex doesnt mean looking at pornography on your computer. It means using your fingers to penetrate your partner. Using gloves, or finger cots (essentially little condoms for your fingers), can reduce your risk of being exposed to any viruses or bacteria that are in your partners secretions. Just as with condoms, you should always switch gloves if you move from penetrating the vagina to the anus, or vice versa.
Rimming
Rimming, or oral-anal contact carries any number of potential health hazards. There is a risk of infection not just from STDs but also from intestinal bacteria. It is important to use a dental dam when performing oral-anal contact to keep yourself safe. If you dont want to buy a dental dam, they can be made by cutting a condom down one side and unrolling it, from a latex glove, or even from non-microwaveable plastic wrap.

