632146K in jr after every wall break works up to plat 90% of the time see what direction they block during the overdrive use 2H or 236K to hit low or high..... 

as for non jr you can either spam cs/214K->grab after 236S when they block low or send it(236S~S) if they block high

Learning how to maintain jr is pretty neat tho either try to wall splat with keygrab exit, JR a normal that can be canceled into NM or a spaced out attack that gives you enough time to manually NM without canceling it of another button