I found a thumbless close grip helped. I also squeeze the shit out of my glutes. I took my OHP from 235 to 285 very quickly by tweaking those cues and doings singles every week.
315 is a big goal of mine but as of right now I do not even train my OHP. I hit 280 last week strict but I am too focused on my bench to fit in OHP right now. Will start back in the summer and see what a year of legit OHP does.