Overhead Press

Okay, so I've been doing StrongLifts for about a month now. I've mastered every exercise except for the overhead press. Whenever I do this exercise, I don't feel like I'm doing it right. It's really hard to explain this in words, but I've had a trainer and a random guy at the gym watch me once do it. The trainer said that I was using my lower back too much, and he was right: I was feeling A LOT of stress on my lower back. So to fix this, he said to suck my stomach in and to do some shoulder dislocations. So this fixed the problem. as he told me that your lower back should not activate at all during this exercise.

Next, I have some people like Mehdi from StrongLifts say that your wrists should bend a bit during this exercise as to allow for your elbows to be able to be in front of the bar. However, I did this with very light weight, didn't really pay attention to what my wrists were doing, and just focused on not splaying out my elbows during the descending movement of the barbell. After I finished 5 sets, a felt a bit of discomfort in the wrists of my right hand. So I'm assuming that if I was lifting heavy, my wrists would be destroyed (the same as lifting heavy on bench press with bent wrists, a big no no). So, wrists bent or not? And if not, is it still possible to achieve 'elbows in front of the bar?'

Finally, if you look up on youtube: how to overhead press (by buffdudes), they say that you bend at your hips during this movement to avoid the bar from hitting your face. However, when I was doing overhead press the other day, I didn't need to do this and the bar didn't hit my face. So... I'm a bit confused... does this rule only apply when you're lifting heavy? And how do you bend at your hips, without activating your back?

This is the most annoying exercise to learn. I actually raged the other day, because I just can't seem to learn it. It doesn't feel right when I do it, but at the same time, it sort of does. There's just sooo much to remember and to do and my brain had an information overload. I told my mom and she said she would pay for an hour session with a personal trainer just to learn this exercise. I really want to do that, because when I go to the gym, and ask the personal trainer there, he doesn't really seem to be 'in it.' I dunno, maybe its just my perception. I dunno.

At the same time, I really want to just drop this exercise and just do standing overhead presses with dumbbells. But Mehdi says I ahve to add 5lbs each time. And when you get to higher weight dumbbells, they go from like 30 - 35 - 40. So you would have to increase weight by 10lbs each time. And that would be too much. How would you get past this problem? Would you do like 5 sets of 5 with 30 lb dumbbells two workouts in a row, and then switch to 35 lb dumbbells the third workout?