How to Perform the Cable Lateral Raise
The deltoid muscle group is made up of three heads: anterior, lateral, and posterior. Many athletes emphasize exercises targeting anterior or front deltoid-dominant which can lead to overdevelop front delts and underdeveloped lateral and posterior delts. As a result, they have an unbalanced physique, poor posture, limited range of motion, and an increased risk of muscle impingement.
No routine is complete without a shoulder isolation exercise focusing on the lateral delts.
The cable lateral raise is an exceptional isolation pull exercise used to target the lateral or side deltoid muscle. This anterior or front deltoid, middle and lower trapezius, supraspinatus (rotator cuff), as well as the inferior digitations of the serratus anterior (boxer's muscle) act as supporting muscle groups during the exercise. 
Supporting muscle groups assist the target muscle group(s) during the movement. The upper trapezius, levator scapulae (upper shoulder/rear neck), wrist extensors (outer forearm) act as stabilizers during this movement.  Stabilizer muscles help maintain a posture or fixate a joint by contracting without significantly moving. 
Shoulders can be hit with a higher frequency and volume compared to other muscle groups because they're comprised of a higher percentage of slow twitch, endurance muscle fibers.
How to Perform the Cable Lateral RaiseBegin by approaching the cable tower, moving the pin heights on both sides of the tower to the lowest possible setting, attaching the single handle pulley attached to each side, and selecting the appropriate working weight. Although you can perform cable lateral raises one arm at a time, this write-up will walkthrough performing the exercise using both arms at the same time.
don't use 10lbs on one side and 20lbs on the other side. Uneven loading won't improve your gains and will likely lead to an injury. Compared to the dumbbell lateral raise the cable lateral raise provides a more uniform tension and even muscle stimulus throughout the movement. As a result, you may find yourself needing to start with a lower weight because there's more tension in the typical sticking point midway through the lift.
If this is your first time performing the exercise then pick a conservative weight that you can safely lift for 8 to 12 repetitions.
Once you've selected the appropriate working weight, pick up the handles with a neutral/hammer grip (palms facing each other). Ensure your right hand is holding the handle from the left side of the tower and the left hand is holding the handle from the right side of the tower. This will maximize range-of-motion. If the cable tower is relatively wide then you can walk over to one side, pick up the handle, and then walk to the other side and pick up the other handle.
Before beginning the exercise you should be standing in the center of the cable tower so that the tension on each cable is about the same. For many cable towers, this means you're standing directly under the pull-up bar. Take a stance in between hip and shoulder width. You can use a traditional grip (thumb wrapped around the fingers), hook grip (fingers wrapped around the thumb), or a false grip (thumb and fingers on the same side of the handle).
After setting your stance and grip, take a deep breath, brace your abdominals for impact and stand tall with an upright posture, chest high and shoulders retracted. With the handles starting at your sides, but not resting on your hips, and your elbows straight (but not hyperextended) or slightly bent, begin raising both arms simultaneously.
Maintain the same elbow position and continue raising both arms until your elbows are at the same height and in-line with your shoulders. Hold the cable handles at this height for 1 to 5 seconds and then slowly lower the handles in a controlled motion back to the starting position. Complete for the desired number of repetitions.
During both the raising and lowering portions of the lift ensure your elbows stay in-line or slightly higher than your wrists, the chest remains high, and the shoulder blades remain down and retracted. If you find yourself swinging your body, raising your shoulders towards your ears, or allowing the wrists to raise higher than your elbows then the weight it too heavy.
This exercise can be performed using straight sets, pre-exhaust sets, drop sets, rest-pause sets, supersets, tri-sets, giant sets, paused reps, partial reps, forced reps, or slow negatives. As with any exercise, the two most important components are high-quality form and progression. Progression can take a variety of forms (e.g. more weight, sets, or reps, decreased rest period, improved rep quality, etc) but strive to improve every time you walk into the gym.
Cable Lateral Raise Form TipsUse One Arm - If you're having trouble getting a good lateral deltoid contraction or if one lateral deltoid muscle is lagging in size or strength compared to the other, perform the cable lateral raise with one arm at a time. This will help improve the mind-muscle connection during the exercise as well as even out any imbalance that may have developed between hamstrings.
To perform a one-arm variation simply take one hand and hold the tower or place it on your thighs or hips and raise the cable using the other hand. Perform the desired number of reps and then switch hands.
Avoid Momentum - The cable lateral raise provides maximum benefit when it's performed in a slow and controlled full range-of-motion. Check your ego at the door and don't attempt to lateral raise 100lbs.
Excessively heavyweights on this exercise will lead to body swinging in an effort to generate enough momentum to raise the bar. This momentum dramatically increases the likelihood of injury and minimizes the stimulus of the target muscles.
Hold at the Top - If you're looking to increase intensity then experiment with holding the cable handle at the top position for 5 to 10 seconds. This will increase time under tension and the burn in the lateral delts. Increased time under tension is an excellent variable to adjust for progressive overload and enhanced muscle growth.
Rotate the Wrist - If you find yourself allowing the wrist to raise before the elbows then try slightly rotating wrist so that the pinky finger is facing towards the ceiling and the thumbs are pointing at a 45-degree angle with the ground. Many trainees say this wrist rotation gives the appearance of pouring an imaginary glass of water on the ground.
Regardless of what cue you use to utilize this tip, you should experience an enhanced engagement of the lateral delts and less engagement of the trapezius muscles.
Strap Up - If your grip gives out before your shoulders then don't be afraid to use straps. The focus of this exercise should be to work the lateral delts and appropriate supporting muscles. Popular strap options Versa Gripps, Valeo, and Spud Inc.
References1) "Cable Lateral Raise." ExRx (Exercise Prescription) on the Internet. N.p., n.d. Web. 29 Oct. 2015.
2) "Kinesiology Glossary." ExRx (Exercise Prescription) on the Internet. N.p., n.d. Web. 29 Oct. 2015.