Place your forearms flat on your desk. Your forearms should be about shoulder width apart, with your elbows directly under your shoulder and a 90 degree bend at your elbows. Your body should be a straight, sloping line all the way down to the balls of your feet, which will be planted on the ground. Make sure your feet and heels are together. Gravity will want to cause your hips and back to sag. Try subtly curving the middle of your back, like you are doing a crunch, pushing it towards the ceiling. Once you have the position, try holding this position for 10 to 20 seconds. Rest for 10 seconds and repeat 4 to 8 more times.
SPECIAL NOTE: For all the In the Gym: Cable and Dumbbell exercises pick a weight that you can do for 8 to 12 reps fairly comfortably and with perfect technique. After a couple of weeks of performing at this weight and with perfection, on then, move up to a slightly heavier weight that feels challenging once you get to that 8th or 12th rep. Once you feel absolutely confident in performing every rep with absolute perfection, only then, go to a heavier weight that is challenging you through out the set.