Biggest tip I could give anyone to get huge traps is to just do plate shrugs with a 45 in each hand. Squeeze and pause at the top, you can't pause with a bar loaded to the gills with plates.
The trick is to hold whatever you're pulling in as close of a straight line from the traps as possible. If I drew a line straight down your body from your traps you'd see that the grip of a 45lb plate close to the legs falls closest in line with the traps. Dumbbells make the hands stick out more, a barbell puts a different grip on it, the most natural way to do them is to hold a 45 lb plate at sort of a 45 degree angle on top against each quad. Shrug up till the traps come to ear level , pause for 1-2 seconds and then lower as far as the traps will stretch down. You'll know you're doing them right when they get hard around rep #15.