Lower Ab Crunches :

Lie flat on your back on the floor, legs raised, knees bent and lower legs folded. Push your lower back into the floor. Place your hands by your sides, palms facing the floor. Raise your backside and hips slightly, breathing out at the same time. As you crunch up push your lower back into the floor and squeeze the lower section of your tummy (pelvis region) as tight as possible. Lower your hips and backside back down to the floor and repeat. You should feel a burning sensation in your lower tummy area and upper pelvis.

Floor Crunches
(you can also use your ab roller/ frame for this exercise)

Lie flat on your back on the floor, legs bent, feet flat, pushing your lower back into the floor. Clasp your hands behind your neck, keeping your elbows back, in line with your head. Crunch up slightly, raising your head and shoulders, breathing out as you crunch. As you crunch up push your lower back into the floor and squeeze your tummy as tight as possible. Lower your head and shoulders back down to the floor and repeat. You should feel a burning sensation in your upper tummy area and midsection.

Side Crunches
(you can also use your ab roller for this exercise)

Lie flat on your back on the floor, have your knees bent and legs twisted to one side. Your lower body should be twisted to the side but your upper body should remain straight and flat on the floor. Have your hands by the sides of your head and your elbows back. Crunch up slightly pushing your lower back into the floor, raising your head and shoulders, squeezing the side of your waist. Lower your head and shoulders back down to the floor. Repeat the exercise until you have finished your reps. Then change to the other side.