When you're trying to avoid pregnancy, a one-size-fits-all approach isn't the best way to go about it. Of course you should consider your doctor's recommendation first, but here are a few ways to choose the best birth control for you. Consider risk factors you might have – genetics, disease, allergies and even lifestyle factors such as smoking and obesity can affect your health and dictate which contraceptives are safest to use. First, consider what you want a contraceptive to do – prevent pregnancy, prevent disease or both. Barrier methods such as condoms are the most effective in preventing disease, but it's important to keep in mind that they're not perfect every time. Only abstinence will protect from disease and pregnancy. For women who are in monogamous relationships and prefer not to use any outside birth control, then fertility-based awareness methods – aka the "rhythm" method – may prevent pregnancy. Women can track when they ovulate to prevent pregnancy during those times. The method is about 75 percent effective, according to Planned Parenthood.