Increase squat, dead, press, row which will grow your overall base - a lot will go to your arms as you can't press and row without them. Then do some basic curling or extensions.
No magic. All the people using exotic arm training and magical splits without doing big work have a really hard time - take a look at all the noodleboys in the gym - if there was a magic combo, they've have found it due to sheer numbers and brute force effort. I have yet to see someone squatting and pulling like a beast have any issue building big guns with some basic curling and extensions added in to supplement.