The proximal insertion point of your traps begin at C1 (your neck) and inserts distally in the middle of your thoracic spine. People always differentiate the neck from the traps, it's the same muscle group, but at a different region of that same muscle group. You can't stimulate the upper traps without stimulating the proximal insertion point (C1-C7).
Shrugs ARE pretty direct, either you simply don't respond well to hypertrophy of the neck or you're not using enough weight. Deads, Shrugs and upright rows, like the guy recommended before me are great exercises for big, thick, elevated traps, given you lift with enough weight and at the right sets & reps.
My workout partner can shrug 405lbs just as efficiently as I can, but my traps are much more prominent. I simply respond much better in terms of hypertrophy.
How long have you been working for neck size?