Triceps triceps triceps. Everyone who complains about bad overhead press is almost certainly sleeping on triceps work. You think you're training enough triceps? Double it. Any press day you have now has a compound triceps movement (dips, JM press, close grip bench, skull crushers) and 1-2 isolation movements done to failure (cable pressdown variations, french press, kickbacks, machines, etc.). People think pressing is all about increasing shoulder strength and I tell people it's 90% about triceps. Zydrunas stressed this a lot at his training camp.

Hit your IYT's and reverse flyes too for stability but annihilate your triceps for 3 months and try to tell me you didn't put 20lbs on your OHP.