If you wish to have those desirable wash board abs, it is advisable that you try out these simple exercises.
Pile pose- This is best for the whole body exercise. Stand with legs more than shoulder width apart, feet turned out 45 degrees. You can do the squats as you bring both arms down. You can use weights for this exercise. Again you can do the pile pose by pushing one leg as you straighten the other one. If you straighten the left leg then push the other leg and put it on the inside of the thigh. This way you will be able to tone up your arms, legs, abs and butts all at one time.
Bridge pose- Lie down on the mat and keep your head up. Remember that there should not be any neck movement. Lie face up on mat with keens bent, feet hip width apart on floor and arms by side. Raise one leg up and the other leg should be firm on the floor. Raise your arms up and then make circle with your right leg first followed by the left leg.
Crunches- Nothing can beat crunches. It is best for the abs. Lie down on the mat with knee bent ninety degree. Place hands behind the head, elbows out and crunch up, lifting shoulders off mat. There are a lot of variation about the crunches. Another one that you can try is by lifting up your legs slightly up from the floor and crunching up.