Deadlift: Chest needs to be more upright throughout the whole lift. Like if you have something written on your sternum and you want to be able to read it in the mirror the entire time. You're looking down, which isn't helping. Look 5 feet in front of you or at a spot on the wall right above eye level.
Won't comment on OHP because I'm absolutely horrible at them.
@pinkpater I think that the biggest cause of her buttwink, in this case, is hyperlordosis at the top. In watching the video, I noticed that when she begins to break at the hips/sit back into the squat her back assumes an extreme arch and when her butt tucks at the bottom, her back actually goes from being hyperextended to neutral (or, at least, it appears to be pretty close to neutral when I press the pause button when he hits the bottom of the first rep). Basically her back angle at the bottom appears to be mostly correct and the problem is actually her exaggerated lumbar curve at the top when she starts sitting back. A lot of this might simply be a situation where she is so concerned with the typical "chest up, butt out" cue that she is exaggerating the back angle and hyperextending rather than staying neutral and bracing properly with her core. Learning how to brace with the core/deep abdominal musculature properly and maintain a less extreme back curvature at the beginning of the movement might do a lot to fix the problem, in this case.
Anyways, I'm out. Just thought I would clarify the point.
@dawn16 I have a pretty pronounced arch when standing regularly, so it probably is being exacerbated with the weight on top of my shoulder. I'll try and see what I can do about it, but it's kind of my natural posture.
It's probably related to the core failure in the OHP, so I'll keep working on it. Thanks!
@pinkpater Ugh. I figured as much. I'm thinking it's me compensating for my tight calves/Achilles Heel by trying to get parallel by butt winking. Thank you for the link!