2. Think Symmetry
When climbing or descending a hill, it's best to go straight up or straight down, since this puts equal stress on feet, legs, and hips. Of course, if the hill is steep or the trail follows a slanted line, you'll have to traverse it. The problem with taking a diagonal route is that one foot will always be lower than the other, leading to unbalanced stress on the spine. Equalize the stress by doing frequent switchbacks, if possible.