First I have to ask… Have you ever finished/printed any of your images? Have you calibrated your monitor and adjusted your gamma? The reason I ask is because your images are so very dark and under exposed, they don’t look to me like they would print very well at all. I also notice some WB problems with your color images. This can be fixed in camera, by calibrating, and learning good editing techniques.
Your black and white conversions seem muddy to me, and it’s definitely something you need to work on, unless the problem lies with your calibration and/or exposure.
Another thing I notice is that most, if not all of your images, what I believe to be your subject isn’t the photo’s focal point at all. Placement of your subjects needs more attention. More attention to light needs to be made as well.
Your focus almost always seems centered. This rarely if ever works. Google “rule of thirds” and/or proper composition and learn how to manually select your focus.
I’m not sure if this is the case or not, but your images look as though they were taken in an auto mode with pop up flash turned off. Learn how to meter and read light, learn good composition, take more time placing or posing your subject, calibrate your monitor, and work on your black and white conversions. Then PRINT and finish your work. This alone will improve your photography. By learning what goes into a print/photograph it will change they way you shoot, edit, compose, ect and you’ll see your photography improve.