I think you have good ideas here. I'd start by looking for more dramatic light, either a different time of day or with off camera light. A reflector could help the first one by adding light from the right to better isolate him. Likewise fill flash; either on camera or off can accomplish the same thing.

The first one is a good concept, I would try a different perspective to get rid of, or minimize the background elements. A longer lens with a shorter DOF would help that, but taking it out of the frame would be even better. A wide-angle up close and tight from a low angle is how I see it. Since it's a parking structure, you could also try a longer lens from a low angle too, perhaps from a ramp to that level.

To me the last one is crying out for context. What's she looking at? Why is she standing there? It has nice lines, but that's all I see. It may be because the colors are too close together visually. Honestly if it were mine I'd say I missed the shot and file it away as something to re-visualize. I'd look for a better sky element. Also I think she might work better in the left 1/3 looking into into whatever you place in the sky element. The lines currently lead you to her, but she's not a dominant element in the frame. If the lines lead in to her them to what drew her to be looking over the edge I think you have something.

The sunglasses shot is a nice idea. It already is a sort of face as shot with the screw heads and the object under the nose piece of the glasses. I like that there is a "facial" element without being shown a face.

One last thought. If I find myself trying "make" a shot in or with post, I feel that I missed it as well. The sunglasses shot works ok with the halo's but perhaps remove them or lower the values from around the pink shoes, I find them distracting as they are. They make a nice framing element so they ought to support the sunglasses face element. Right now they draw my eye off the central theme. Try it the either way too, lower the halo around the glasses to emphasize the pink shoes.