Remember that you should not do this if you feel pain. Start slowly. Consult a doctor if you feel pain. starting on your elbow may be a better place to start (if you feel pain in your wrist). Try to do this for thirty seconds, take a two minute break, and repeat three to six times. Ensure that the humerus bone sits well in the shoulder socket; think of externally rotating the shoulder; open your heart. When opening your heart (i.e. extending your thoracic spine) you will notice that your lumber spine will try to follow the extension; prevent this from happening by thinking of moving your lower ribs closer to your pelvis.
Think about keeping your spine neutral. This position builds many muscles, including the obliques, abdominals, latissimus dorsi, and many more. Think about engaging all the muscles in your body - from the your fingers, hands, & wrists pushing strong into the floor, your other hand reaching up to the sky, your legs engaged and finally your feet pushing out and into the floor.
If both of these options are too intense for you then a third option would be to put your knee onto the ground (as opposed to your foot as shown in the video). Supporting yourself with your knee as opposed to your foot makes this an easier exercise and is a great way to get started if you feel that the former was too intense or painful in anyway. Remember - you should never feel pain.
This should feel good. Make sure you're not "dumping into your muscles" as you actively engage each of your muscles. Your breathing can help connect you to your body by consciously thinking of sending the air to different parts of your body as you breathe - four seconds in - and four seconds out - both through your nose. By coordinating your breath with your motion, this helps to bridge the mind-body connection and prevents your mind from wandering off.
When your mind wonders off, you stand a risk of injury as you brain is trying to process too many things and not focused on the task at hand. Always pay attention to what you're doing and be safe.