I know you said "besides shugs," but there are a number of different ways to do them that all seem to work them a little differently. You can do them with dumbells, with a bar, with a bent over row machine (my personal favorite), pulley machines, etc. One way I often see people do it is with a pulley machine set down at the ground. You then grab the strap with one arm, brace yourself against something with the other arm, and do the shugs. When you get done with a set for that side, switch to the other. Doing it this way works your traps at a much different angle than the traditional way, and might be something you want to look into.