One of the most important exercises to shape up your lower body is the back extensions. Back extensions work on a combination of muscles, thereby leaving an excellent toning effect on the entire lower body. Back extensions is one exercise that really puts the lower back muscles, butt muscles and hamstrings to really good work. 

In order to perform back extensions, you need to either locate a gym with the back extension machine, or you will need to purchase one of your own back extension machines. Lie down on the back extension seat, flat on your stomach, so that your face is facing the floor and the back of your neck is facing the ceiling. Hook your ankles and feet around the curve of the roller pad near your feet, for firm support, on the back extension machine. 

Now fold both your arms across the breadth of your chest. Hold your head high, arch your back up. Flex your chest.  Make sure your head and back rise in one straight line, maintaining the same level. Keep rising as far back as you can. Keep practicing over a period of weeks or months till you develop the strength and flexibility to raise your back vertically. For beginners, it is not at all required that you lift your back higher than an elevation that keeps your back parallel to the ground, as it may cause unpredictable stress of injury. , 

Slowly and gradually come back to rest on the seat of the back extension machine, without any jerks or shudders. As you become more and more confident with your work outs, you could start piling up weight plates to your chest for building the endurance. Under all circumstances, never ever attach any weight around your head region or your neck region, as that could cause serious injuries. So while you're going for it, go slow, and take your time. There's no need to do it in such a hurry that you find it impossible and never do it again.

Another very good exercise for your lower body is the ski squats. Place both your feet such that your feet are at a distance of your shoulder width from each other. Keep bending your knees until your position is such that it is around half of the full squat position. Now hold this position for roughly 10 to 15 seconds. Now sink lower by another 2 inches and hold this second position for another 10 to 15 seconds. Now again for the third time sink lower by another 2 inches and again hold for 10 to 15 seconds, before rising all the way up gradually in a controlled manner. 

As your body develops more and more strength and your muscles gain endurance, start increasing the number of reps of this exercise. These exercises will really shape up your lower body. With these exercises, you will be all set to go to the beach front and flaunt those beautiful butts, those well-defined thighs and those really sexy calves on your lower body. A little discipline, dedication and focus are all you need to get that dream figure.