I think your photos aren’t bad. I mean that your shots are better than a lot of the stuff you see on here. The questions I would have you ask yourself are: Why am I taking this picture and what do I want my subject to look like? I know this sounds ridiculously simplistic but that should be your first question before pressing the shutter. Why? Because your answers will dictate all your aesthetic choices such as….the location where you shoot, what you include in the frame and what you exclude in the frame, how far away you are from your subject, how much of your subject is in the frame, where you stand in relation to your subject, what lens length to use, what type of light will help with the type of mood I’m after etc…
You are doing a pretty good job of keeping your compositions clean. That is a lot of the battle with people starting out. One suggestion would be to move around, try shooting from a variety of perspectives. Most of your subjects are dead center in the frame. This has a tendency to make the image too static. I’m not saying never do that but as the saying goes;”Learn all the rules of photography, then break them”.
My last suggestion is never underestimate the drama and emotion that different light can have on a subject. Think of how filmmakers in Hollywood [who make the BIG bucks] use lighting to change the way you feel about a subject. Would a guy running at you with a chainsaw be scary if he did it in broad daylight? Try reshooting [if it’s possible] some of your same shots but shoot them in morning light, at dusk, contrasty light, light filtered through a window or a screen door, candle light etc… each of these will make your image feel completely different.
Actually this is my last suggestion: Look at other professional photographer’s work you like. Ask yourself what choices did the photographer make [look at the list above] and how did those choices enhance the look, feeling and meaning [to you]. You can always borrow an element you liked in their work and try to use it in yours. I don’t mean literally copy every part of their image just one element, like the way they used the light. Once you do this you will start to ask yourself these kinds of questions and when you start to find the answers….you will be on your way to being a more conscious photographer!
Two photographers to look at would be; Frank W. Ockenfels and Sam Jones I know there are a million more but you gotta start somewhere.