Hi Paul
Your photos of Willow Star are my favourites, as they make use of natural light so well.
I see in your profile you've said that you don't use lighting (I assume you mean studio lighting) which is great, and a lot of photographers work this way - just using the available light around them (either from a window, a nearby lamp, light shining down a hallway, etc).
I think your photos using available light appeal to me more than the ones using a flash (which is a form of lighting, just less fancy than big studio lights), as they seem more natural, and therefore more in line with what you're trying to achieve, if that makes sense?
I do love seeing photographers work this way as you can get some lovely, unpredictable shots simply by experimenting with what's already there. Maybe you could even try a bit more outdoor work just using the sun (or sunset?) while the weather's nice (I use the term "nice" very loosely here).