The first step is to buy the real stuff. Personal defense spray is not bear spray, so make sure you purchase spray labeled as bear deterrent. One study showed that more than half of the hikers armed with pepper spray didn’t have bear spray. The second step is to practice. In a study of bear attacks in Alaska, bear spray stopped a bruin’s “undesirable behavior” in more than 9 of 10 cases, and 98 percent of those attacked escaped uninjured with using the spray. But get it right. Here’s how.