Set the correct height of the incline bench to have your one hip leaning against the rest and your torso free. Take a position leaning on your hip on the inclined bench. Put your feet firmly in the base against the bottom support roller. Firm up your torso and keep your pelvis in a neutral position. Touch your head with your hand behind your ears with your hands with elbows pointing apart.
Start by slightly leaning forward and while contracting your abdominal muscles lean down and then move upwards. Do the required number of repetitions. Inhale in the lower position and exhale in the upper position. Switch sides and repeat the exercise.
Make sure you have set the correct height on the bench. Keep your torso firm and your pelvis in a neutral position throughout the entire movement. Do not bend forward or backward at the waist. Use membrane breathing to better involve your abdominal muscles.
For greater resistance you can use weights, usually weight plates that you hold to your chest.