Personally i think shrugs aren't the best exercise for traps.
In my experience the best exercises for traps are power snatches (catching the bar at half squat depth or higher)and power cleans. They can be done from the hang or from the floor; i find that if i do them from the hang i tend to focus more on a strong fast trap contraction and thus get more benefit for the traps. Snatches tend to focus more on the traps, but cleans let you use more weight...so i find it's best to mix it up every couple weeks or so. If you don't want to worry about catching the bar you can do jump shrugs instead, just be sure to focus on an explosive shrug at the top.
Also, if you aren't already doing deadlifts you should start, they are essential. Although traps aren't the main focus of deadlifts obviously, they will get work.
I know you didn't ask, but i'm gonna just mention it anyway; i think any strength training routine for just about any athlete (other than olympic lifters) should regularly include these lifts in the routine:
Military press/incline/push press/push jerks
Rows (preferably bent over rows)
Pull ups (weighted if necessary)
Some form of single leg exercise, preferably bulgarian split squats
If you properly include these lifts in your routine you are pretty much guaranteed to get functionally strong and avoid strength imbalances. If you want a good routine that includes these lifts i highly recommend the Bill Starr/Mark Rippetoe/Glenn Pendlay versions of the 5x5.
Another note: Plyometrics are basically worthless and shouldn't be done until an athlete can at least squat 1.5x their bodyweight with perfect form to at least legal powerlifting depth (hips lower than knees).
If any one has any other questions regarding strength training feel free to pm me. I'm new to training for mma conditioning and such, but i do know a lot about functional strength training.