Hi AirCartman,
I've only been training for a while, and I do shrugs, too, although I only do 6 sets in total: 3 working sets using barbells and then 3 further sets using the EZ Curl bar with light weights. Shrugs work the trapezius muscle to the greatest extent. I was told that as it is a small muscle, along with the triceps (I do both on the same day), so 6 working sets is enough. I only work each muscle once a week - it has been working for me so far!