Like with any other task accomplished with another person, as Jean pointed out, communication is important. Being able to open up verbally to a partner is key to mutual pleasure and ultimate satisfaction.
If you have difficulty in communicating, there are ways to learn. I know I've mentioned this before, and fullmoonma left several comments on yesterday's post about this: Body Electric seminars are designed to do just that; help you express what feels good, what you want to experience in the moment; to ask a partner for what you'd like them to do.
Tantric Massage is another place to learn the skill of sexual communication. Tantric Massuers are trained to help you learn to express what you're feeling and learn control over your body.
The more control you command over your response, the longer you can make a singular sexual romp last. Whether that's alone or with a partner.