i rotate bi's and tri's when i do arms. i figure they have been hit in one way or another at least twice a week with push and pull exercises before i isolate them at the end of the week.
i start with two hand push downs (palms down) 3-4 sets up to 160lb, then go to seated double dumbbells (not alternating because i don't like twisting my spine) 3-4 sets up to 90lb then tri extensions/ pullovers with a easy curl maxing 3-4 set up to 2 45's on ea side then straight bar curls at 225lb (oh yeah I'm a cheatin bitch and when there's a pretty girl around i'll go to 275lb) then single arm cables extensions(palm up) 3-4 sets up to 160lb then single arm preachers w/ 50lb dumbells 3-4 sets (these i do each arm twice to make one set) then some lite kickbacks 3-4 sets w/ 50lb dumbells and finish with stading double bicep curls on the cables @160lb each. whole arm is pumped and ready for the weekend. the cables sound like a lot of weight but it is really not because the pullies take about half the weight out of the exercise. the straight bar will take a lot out of you rather your "cheating" or not.