Shoulder width is everything — training for aesthetics

If you care about aesthetics, your shoulder-to-waist ratio is the single most important variable you can influence through training. The golden ratio waist is roughly 0.7 times your shoulder width. Most men aren't limited by their waist — they're limited by underdeveloped lateral deltoids.

The lateral (side) head of the deltoid is what creates the wide shoulder appearance. It doesn't get adequately trained by pressing movements. The key movements:

Lateral raises are the bread and butter. Done properly — not swinging, not shrugging, controlled, with a slight lean forward to put the lateral delt on better stretch — they build the shoulder cap that creates width. 4-5 sets, 15-25 reps, done frequently (3-4x per week) with moderate weight.

Cables > dumbbells for laterals. The dumbbell version has zero tension at the bottom (where your arm is hanging by your side). A cable from below keeps tension through the whole range. If you can't access cables, lean away from a fixed object while holding a dumbbell to approximate this.

Rear delts matter for posture and thickness — face pulls, rear delt flies, and rows all contribute. If you have forward-rounded shoulders from neglecting rear delts and upper back, your front-on width is masked by the hunched appearance.

Training frequency: delts recover faster than large muscle groups. You can hit them 3-4 times per week with moderate volume and make faster progress than hitting them once heavy. The lateral delt especially responds to high frequency and moderate weight more than trying to go heavy with dumbbells and compromising form.

The clavicle is your bone limit — you cannot train yourself wider than your bone structure. But most people are far from their bone limit.

The rear delt and posture point is one I don't see emphasised enough. You can have wide clavicles and decent lateral development but if your shoulders are internally rotated and you have kyphosis, you look narrower than you are. Fixing posture sometimes visually adds inches to shoulder width without changing anything else.

What rep range for someone new to training? I've been doing 3x12 on lateral raises but not sure if I should be going heavier/lighter.

For laterals specifically, heavier is rarely better. The lateral delt is a small muscle with a short moment arm. Most people swing and shrug to get heavy weights up, which trains traps and uses momentum rather than the delt. Use a weight where you can do 15-20 reps with strict form and really feel the lateral head working. Progressive overload still applies — add reps before adding weight. 3x12 is fine but I'd extend the rep range to 15-20 and add a set.

Worth mentioning that upper body aesthetics also benefit dramatically from trap development. The upper traps form the slope from your neck to your shoulder, and well-developed mid/lower traps add to the thickness and posture of the upper back. Shrugs and face pulls both contribute. Don't neglect them in favour of only lateral delts.