Home studio natural light self-portrait

In the interest of improving my skills as a portrait photographer I am embarking on a project, who knows how long, to master every piece of equipment I own and try as many practical tips and ideas as possible from the many books, YouTube videos and Flickr groups I have access to, as well as my own.

I will appreciate any and all practical comments on what works and does not work in these tests, what I can improve and what new techniques I should try.

This is lit entirely by the window in my studio. No flash. F/7.1 and 75mm to achieve the front to back sharpness. No processing for light or color in Lightroom. Impressive? Or lazy?

The good: this pose works for me and most clients

The bad: it is the only pose I know, at least for myself.

Next steps: try 85mm, it is supposed to be "the" portrait focal length.

Try same lighting with flash lighting the wall to make it white (necessary?). Try flash highlighting hair (use snoot?)

Try turning more into the window to see if more even lighting is a plus.

Is fill flash needed at all? Could try that.

Work out deltoids and triceps more.

Try the "turtling" posing technique -- unless it was already used here.

Keep better notes while shooting -- important!