Another ditto about reflectors and fill. Also want to echo the notion of depth-of-field: you need to control it better. Two shots could use a little more depth of field - #1 and #4. I know it's tempting to think of your images in terms of f2.8 from your Rollei's ground glass, but sometimes it's hard to tell when waist-level viewing on that small of a screen how sharp something really is. Start paying attention to the DoF guide on the focusing knob- it will help visualize what is and isn't sharp. Assume the human body takes up a 3' x3' square when standing still, and a 6'x 6' square when moving or gesturing. Do you have 6' of DoF at the given aperture when shooting the woman out in the desert? Is all of her contained within that 6'? Obviously when shooting a tight head-and-shoulders (or closer) portrait, you're not going to need that kind of volume, nor would you want EVERYTHING necessarily in focus. But what is/is not in focus should be deliberate, regardless.