@rickyw
I'll piggback on both the comments made above.
It does look like you are laying back a lot on the left. It's not just a matter of avoiding lumbar extension. It's more that it doesn't look like you are catching the bell in the rack in a planked up/zipped up/spring loaded position, so you don't have a strong base to press from.
The right side looks much more solid.
Moving your stance in from the clean can help you wedge under the weight more strongly. Get the working side hip under the bell so your have more of a straight line of support under the weight (bell-elbow-hip-foot). Move your non-working side foot, so your working side foot can stay rooted under the weight. You can even move the non-working foot during the float of the clean so you are receiving the bell already in your pressing stance.
Personally, I've never gotten anything out of the "make a fist with the off hand" thing. To me, it's a distraction of attention from the more primary aspects of the lift and siphons off "neural drive" into an area that isn't really necessary. When grinding through a sticking point, I find it more useful to focus on contracting the glutes and bracing the abs, which seems to have a more direct effect on stopping tension leakages (for me).
Finally, own your lockout. Strongly fixate the bell overhead in a stable, squared up position before lowering. You worked hard to put that bell overhead. Enjoy the fruits of your labor. Show it off. Savor it. Own it.