Single Leg Box Jump

Stand facing the box on one leg, the other held slightly off the floor. Load through your standing hip and knee, swing your arms, and drive up off that single leg, landing on the box with both feet together for stability. Give yourself more of a bend to absorb the landing than you would jumping off two legs, since all the takeoff force came from one side. Step down rather than jumping back off, and reset fully between attempts before switching legs. Keep your standing knee tracking in line with your toes on the takeoff rather than caving inward under the load.