Working your legs will do more than make them look great peeking out from under a skirt. A strong lower body makes it easier to do everything from hiking to climbing stairs.
Lean against the wall with your ball in the small of your back, as shown. Hold a weight in each hand. Make sure your shoes have good traction, because your feet need to be out in front of your body a bit. Lower slowly until your knees are at 90-degree angles (no lower), then return to the starting position. Firms up: Glutes, hips, thighs
Stand with feet together, arms at your sides. Take a giant step to your left side. As you plant your left foot, bend your left knee and lower your butt back toward the floor until your left thigh is nearly parallel to the floor. Do not allow your left knee to jut over your toes. Bend forward and touch your left ankle with both hands. Then push back up to the starting position. Repeat on the other side. Alternate for a full set on each leg. Firms up: Inner, outer thighs
Stand with your legs wider than shoulder-width apart, toes pointed outwards. Hold arms out to the sides and slightly forward (place a hand on a chair for support, if needed). Keeping heels firmly planted, bend knees, dipping your butt until thighs are nearly parallel to the floor. Pause, then slowly straighten legs and rise up on the balls of your feet. Lower heels back to start. Firms up: Glutes, calves
Stand with feet hip-width apart, holding dumbbells by your sides. Take a giant step forward with right leg. Immediately bend right leg and slowly lower left knee toward floor. Keeping both feet in place, straighten the right leg, lifting body upward. Lower again and repeat a full set. Switch legs. Firms up: Glutes, thighs
Place ball against wall. Lie face up with your feet planted on the ball as shown. Squeeze your butt muscles together and tighten your body so that it forms a flat bridge. Hold for a second (longer as it gets easier), then lower to starting position. Firms up: Glutes, hamstrings