Okie dokie, first things first, you need to get yourself a lightbox. Even with a camera phone, a lightbox makes all the difference in the world in terms of showing off detail and not having a cluttered look to the pic. That in turn makes it much easier for people to critique your work and give advice. ANYWAY, onto what I see:
Lucius Crew: They look rather plain, I don't see many shadows, and the pooches need to be pushed a lot more in terms of shades and highlights.
Lucius: You have a super solid paint job going on with him. The brown looks leathery and awesome, but like you said you're a bit uninspired and you'll maybe go back and highlight more. I say that is the direction you want to go. From the looks of it you have a base color and a wash with possibly the base color reapplied. That's way cool for TTQ, but you my friend are better than TTQ, so push yourself a bit more with your highlights. I also hope you work on his legs and feet more, it's way too white.
Showgirls: I love where you are going with these ladies and the cool white always looks good with the blue shades. Work on the skin a bit more. If you look at human skin, there are a lot of tonal qualities. I for example have a pinkish quality to my skin, when compared to a friend of mine who has a more yellow cast to her. I think adding a wash and highlighting up a few more times on the skin would make them look a bit more realistic. My only other issue is with the back of Colette's jacket. the transition from blue to white is just a little too stark for my tastes.