In case no on knows, I'm slightly obsessed with developing my traps. I shared a card about the insane traps on Micquel Wright, who's got traps for days a little while ago. You can see that card here, and you should because his traps are KILLER!!!!!!
DUMBBELL SHRUGS: 4 SETS- 15 REPS( PAUSE AND SLOW NEGATIVES)
UPRIGHT ROW SUPER-SET: 4 SETS 8-10 HEAVY/8-10 LIGHT
OLYMPIC BAR SHOULDER SHRUGS: 4 SETS 8-10 REPS
Always practice good form and posture. Keep the ego at the door and use weights that you can manage correctly.
Also, if you want to see improvement and gains, then you need to train that body part twice a week.