For most people, leg day is the most challenging workout of the week. And it should be. In order to engage those big muscles in your lower body, you need to select heavy weight and be willing to push the intensity.
I like to prescribe box squats because they help people squat to a specific depth. Having the box there as a guide and as a support can be really helpful when you're learning how to squat properly. The box will also allow you to put on heavier weight than you may normally do for 6-8 reps.
Remember to keep your rest periods short for the majority of the workout. The more efficient you can make your workout, the less time you have to be in the gym and the more time you can spend enjoying other aspects of your life.