this is what my thumbs usually look like, to start. as i've mentioned elsewhere, i'm left handed so i usually start my thumbs on the right side of a page, then work left. although sometimes (like here), the left side fills up with corrections, notes etc.
a few notes:
first off, as you can see by the drawings of senator kincaid for page 11 panel 1, the camera is looking down at him, from maria's view. the following panel shows her from his view, helping to establish the mano-a-mano nature of the scene. i have slowly learned over the years (and from the chiding of wiser artists) the importance of really working your camera to sync with what the characters are experiencing.
also re: kincaid. i did several designs for him before, i 've had a pretty good idea of his look before this. but i took another stab at his design with this specific scene (and panel 11-1 in particular) in mind. sometimes you need to take your designs on a test run to see what works in practice, not just theory.
i think you should avoid pure profile or head-on views unless necessary, they are formal and can break the organic flow of a panel or page. but in this case, maria entering the the car is a pretty formal event, so i went for it.
(i generally try to keep movement from left to right, the natural direction for the eye to move. unless you're reading in japanese, in which case "abu nai! ABU NAI!".)
i usually have a very loose script at this point -- i don't belabor it, since i'm the artist, and since i know i'll be changing things once the art is in, anyway. i only write enough in the thumbs to clarify who is saying what and when, etc. in this scene, since the dialogue is so central, i worked it out much more thoroughly, in particular to make sure that everything will fit later.
finally, when you want to create drama in a scene that is essentially static, consider both angles and depth of field. in this case, while both characters are sitting, the camera suggests kincaid is dominating the situation. also, having a strong sense of foreground (kincaid), middle ground (maria), and background (guy in rain) adds visual interest. it's not a matter of having details, it's a matter of suggesting people moving through and operating in a world, not just sitting on a page.
also, i was watching old crime films while drawing, so hands and faces from that popped onto my paper. old films are great because... well, because the just are, dig it? but they're also great for stuff like that because they use more normal shots than more stylized modern films. characters and the cameras jump around less, there are fewer extreme close-ups, it's much more like watching stage performance (which it had, after all, only just evolved from). because they were just black and white, they also had very carefully thought out compositions in terms of light and depth. noir is naturally one of the best genres to appreciate this, since the visual play of light and dark was so central to the metaphorical play of light and dark in the material. but tons of old films (hitchcock and most bogrt crime films come tom mind) are also great.