kneeling dumbell shrugs work great,they brought my traps up from nothing to decent for my build,people may look at you like your retarded but they kill the traps
some people try to get cute with this exercise---straight up(as high as you can go with a relaxed head)pause at top and back down. Never roll it-- 5 sets of 10 barbell before you train shoulders(use it as the first exercise for shoulders) not only is it a good warm up but you can go as heavy as possible and it won't effect your pressing movements(meaning you will not feel tired after doing these) just one exericise 5 sets of 10 with barbell--then next time use the dumbs----thats it don't get cute with it and train it first and watch your traps grow like crazy.
Another thing is go as heavy as possible but make sure your doing a full movement. you see in the gym all the time guys loading some serious weight on the bar and moving it like an inch an pushing with there legs. These guys use like 5 plates on each side but have trouble with 225 on the bench. You get the idea. Keep arms slightly bent and locked. Shoulders back-----make sure your neck is nice and loose before doing these. I'm sure all of us have pinched a nerve on this exercise more then once. peace
Also, when you are doing shrugs, with any type of equipment, be sure and keep your chin down towards your chest, this will allow you to get a full range of motion resulting in a maximum muscular contraction.
No offense to you, but, this is wrong and bad advice for two reasons:
1.) Keeping your head down and forward in shrugs will leave a big door open for cervical spine injuries. This is also not just with shrugs.
2.) Increased range of motion will NOT cause maximal muscle contraction. Maximum muscular contraction comes from stimulation of increased fibers of muscle activated (motor units), this is in the partial range because you can lift more weight which is what will activate the higher number of and larger motor units.