There is nothing prettier than shapely legs and a round back side! I hear all the time...I want to tighten up my thighs, and lift my butt. Lyposuction aside, you have to build the muscle.
All hail the stiff legged dead lift! I change it up a little by adding a step and a stretch. Stand on a step about 5 inches from the floor. Bend at your knees to pick up the weight. I use dumb bells or a barbell. Enough weight to feel it, but not too heavy. Start with about 30 to 40 pounds, if you are brand new, 20 lbs. Straighten your legs and let your upper body hang over.. with tightened abs of course and always! Squeeze your glutes so tight that it lifts you up just enough to keep the tension on the muscle the whole rep. If you go too high, you release the tension. We want "burn" throughout the entire motion. Keep squeezing your buns as you lower back down and stretch past your toes (that's why you are on the step). Then repeat. You should never feel this in your lower back. If you do, you are going too high. To set the weight back on the floor, bend your knees again and release them. 10 to 12 reps, 3 to 4 sets.
For a video demonstration of this exercise, click (or copy and paste) the following link:
Let's keep 'em high and tight!
Flower Mound Personal Trainer