This is a great exercise to really target your glutes and hamstrings. Choose dumbells that aren't too heavy as the idea is to squeeze your glutes on the way up and down the movement rather than trying to move weight.  The weight is there as counterbalance. Firstly stand with your feet slightly apart, then slowly raise one leg back which the dumbells go towards the ground.  You'll have to focus on a spot ahead or on the ground so you don't lose your balance. left: roll mouse over Monty to see movement

Use your glutes to provide stability and balance, this is what's going to give your butt a great workout.  The leg you raise to the back should be more straight than bent while the front leg is slightly bent as you lower the weight. 

As you straighten up, lower your straighten leg to the ground but don't fully put your foot back on as you'll be raising the leg backwards again thereby keeping your glutes tight.

After 10 reps, do the other leg. After 3 sets of 10 reps, you'll know where your glutes are!!

Static Front raise + Lateral Raise In this variation of the lateral raise, raise one arm to the front as if doing front dumbell raise but hold it there. Now raise the other arm to side as if doing lateral raise.  The challenge is to hold your front dumbell raise while doing 8 reps of your lateral raises in good form.  After 8 reps have a 1min rest, then raise your other arm to front and do lateral raise to other arm.   Check out Monty's action by rolling mouse over pic