for bis i like good old style concentration curls... just 1 burn out set, 20 reps or more with a light weight at the end of biceps training
personally i bend right over (no homo) and let my arm hang and stick my arm straight down so that i curl perpendicular to my body line

the pump from this movement is amazing
for tris i prefer 1 set of single-arm kick backs holding a 10 pound plate at the end of triceps day (this is a trend with all of my training, i end most muscle groups with a light 'pump/burnout' set)
once again i complete the movement with my torso bent right over and with the weight parallel to my body

the point of these movements is just to fill the muscles with blood until they cannot move anymore
i train tris and bis on separate days