You are already taking really good pictures so you just need to learn some of the fundamentals to take even better pictures.
1. Keep the background in your pictures clean and simple with little distractions. The eye has a way of focusing on what it see's and it's funny as it tends to find the distracting things in images first.
2. Learn to judge the quality of light and learn to determine if it's cool or warm looking. The cool light then to have too much blue in it and makes objects look cold. Warm light has a slight yellow cast to it and is great for people shots and landscapes. Pictures of objects are better in Neutral light because the colors are truer.
3. Focus as close as you can to eliminate as much of the background as you can. You are actually cropping in the camera.
4. Learn to shoot your camera in aperture priority whenever you can because that controls the depth of field and how deep the focus zone is. Things in front of the zone or behind it will be soft and out of focus. The wider the aperture like f2.8 has a very narrow focus zone so parts of the gun will be in focus and some out.
5. Most modern digital cameras to day have the sweet spot in the lens at f8 so when you can use that f stop because it's the best that lens can be in terms of sharpness and color resolution.
6. Get a good photo software package like Photoshop and buy a book to learn all the tools. You will be amazed at the things you can do to an ordinary in focus picture to make it look way better then when you started.
Most of all practice, practice, practice and study your results so it becomes a learning process.
You can email me if you need any other questions asked.
A couple of my photo pictures
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