What is it that makes someone's photos look professional? Are they just getting lucky? Let me tell you now, it's not luck. If no matter how hard you try, your photos are still turning out amateurish and bland, then this post should help you out.
Let me start off by saying, this is a loaded topic to try and cover, but I'll give you the three easiest ways to make your photos look better.
The three biggest things to focus on are composition, where your focus is, and editing. For example, If I'm taking head shots of someone, I need to keep a few things in mind. Am I taking the photo from a flattering angle, and composing the shot in a way that looks good? What's in the background - is there anything distracting? Am I cutting off any body parts at weird spots (ie: someone's wrist, elbow, fingers, etc.)? Make sure to use the rule of thirds to give a boring photo a bit more interest. If you keep your subject in the middle of the photo and have a lot of empty space all around them, then your photo will lack interest.
Next, I need to think about where the focus is going to be. Obviously when it comes to headshots the focus is the persons face, but that's not all. I'm a huge believer that the focus should be right on your subject's eyes. If the focus misses and hits your subject's ear or nose, it can really make your photo look distracting and bad.
Lastly, spend time with your editing. Shoot RAW and try to give your photo some emotion. Bring out colours, add some contrast, convert to black and white. One thing that helped me with editing was looking at some photos that I like from other photographers and thinking, "What is going on in this photo that I like? Do I like the crunchy contrast, the exposure, the white balance, the punchy colours?" And then I would try and replicate their styles into my own work and then make it my own.
Photography is all trial and error. With lots of practice and education, you will eventually have your own shooting and editing style. For now, just get out there and shoot and have fun!