You wanna look bigger? Grow your lateral delts.
The mind is funny, and even if you're 6'4" and 200 plus lbs, you may actually look smaller than someone who is 5'8" 165lbs. This is because of proportions - mostly the shoulder to waist ratio. Now, you can get leaner, but you can't shave bone off of your hips. Or at least you shouldn't!
But, what you can do is grow your lateral delts on your shoulders and actually extend the width of your upper torso!
This is a great lateral delt exercise that allows you to focus on JUST the lateral delt. I like to lean a little forward and bring the Dumbbell in front of me so I can get a longer range of motion and put all the force on the lateral delt.