Have you tried pull-ups & chin-ups for your Bi's & dips & closed gripped push-ups (all weighted or non) for your Tri's?That's how I got the base for my arms in the early days.I still love rocking them out from time to time.
Well the past month I've been doing a lot of chins and cg bodyweight triceps press (I'm not sure what they're called) I have noticed slight improvements, but the main thing for me is prioritising them. Noticed a HUUGE difference in triceps while doing heavy JM presses like a mix between a skully and cg bench. It really isolates my triceps, and allows me to pack on the weight. I usually always do weighted body weight triceps dips need to always do as a 2nd movement coz it destroys my elbows. For biceps I've noticed heavy cheat curls are really starting to work, like a little swing to get the bar up then controlling the negative.