There are sexually active couples out there who have managed for years to prevent the spread of the disease from one partner to the other. It takes care and attention to detail, but it is definitely possible.
First, try to avoid having sex when there are any blisters or sores present. Having sex during an outbreak is the easiest way to give someone herpes.
Next, use a condom when you have sex, sores or no sores, and be sure the condom covers all the skin of the penis. Any exposed area opens the possibility of infection.
Beyond safe sex practices, for those with recognizable symptoms, not spreading the virus hinges on knowing when a flare-up is occurring even before any cold sores show up. Most often, that means looking out for a "tingling" sensation in and around the infected area. Sometimes, the skin has a mild burning feeling, and muscles nearby may feel like they're "asleep."
For those without recognizable, symptoms, it's a question of being tested. If you're sexually active, and especially if you find out any past partner is infected, get tested for herpes, either by your doctor or at a clinic. For asymptomatic carriers, being aware of your condition and using a condom absolutely every time you have sex can dramatically reduce the chances of infecting someone else.
If you do find out you're infected, unfortunately you're stuck with it. There's no cure for herpes, although there are medications that can ease symptoms and products and home remedies that can reduce discomfort during a recurrence (see the links on the next page).
The good news is, recurrences may let up after a few years, and you'll no longer have to deal with the sores. But you should always be careful not to spread it, even if your recurrences stop or slow down. There are few things worse than giving your partner an STD.
For more information on herpes and related topics, look over the links on the next page.