Lunges are one of the most effective lower-body toning moves you can do, and this front and rear lunge combo hits all the major muscles in your thighs, glutes, and hips (along with your core muscles).
Stand tall with your feet together, arms by your sides. Take a wide step forward with your right leg and lower into a lunge, swinging your left arm forward (elbow bent) and right arm back.
Quickly push off of your right (forward) foot and shift your weight into your back leg as you step your front foot back behind you into a rear lunge, swinging your opposite arms forward and back. Quickly push off your left leg and return to standing, bringing your right (back) leg forward to meet the left. That's one rep. Do 10 in a row and then switch legs for 10 more reps.