Another thing that works INCREDIBLY for me is the way you make the shrug motion. Instead of doing the shrugs in one motion like this: Ex.-----Shoulders all the way down against your sides, then contracting your traps to pull the weight up, all in one steady motion. Instead, do the shrugs in three movements. Position 1 being totally relaxed with weight at sides; Position 2 being half way through the movement; and Position 3 being fully contracted. The trick is to pause for about a second after you get to each of the steps. If you do shrugs like this with the 3 stopping points I described, I think your traps will develop alot quicker. Give it a try and tell me how much bigger your traps are in 6 or so weeks.
*SHYSTER*