When you are fed up with k/d and assignments, relax and work on the Trap Supremacy Gold. It might take a while, but you don't risk you life and can do it on your spare time during the game. It usually takes two well placed lovely Betty's close together to spoil your enemies day.
Mines are nice too.
Why get stressed out, Trap Supremacy Gold is more rare than a gold plated weapon. The unfortunate enemy will see your Gold plated dog tag after stepping in your do do trap.