A lot of people think the key to getting great pictures is the camera, or the lens that they use. I can't count the amount of times I've heard something along the lines of "if only I was using THIS camera." or "if only I had a better lens." Let me tell you right now that if you're that person, you need to cut it out. It's absolutely possible to take stunning photos with nearly any camera that is made today, even your phone, and I'll tell you how to do it.
Firstly, you need to get the proper composition. It's true, the first step to taking a stunning photo is proper composition. You can have the best lighting, gear, camera, lens in the world and if your composition is off, the photo won't look great. Here's an example:
In the first image we have a photo of a cat with a poor composition. There is too much dead space in the bottom right of the photo, That cat is too far off to the left of the image, and he's placed up too high, causing him to look out of the frame, which to me, causes unnecessary tension to the photo.
In the second image we have a better composition. The cat is positioned better in the image, as he is sitting lower in the scene. He's looking more into the frame, as opposed to out of the frame. Setting up the image like this, causes the photo to have a little less dead space around him, which I think is more appealing.
To get and even better composition for a vertical shot like this, it would be ideal to get a little closer and fill the frame even more with the cat, making sure not to cut off important parts of his body. You could also go horizontal with an image like this as well, making sure to keep the same framing of the cat, which would give us a better feel of what the cat may be looking at. But, ultimately, I think vertical was a better choice for this photo, due to the over exposure of the background.
Now that you have better composition, the next step to taking a great photo is lighting. You can have an amazing camera and lens, but if you don't use proper lighting to your advantage, you're photos may still turn out dull. When I'm talking about lighting, I don't necessarily mean using flash, or studio lighting. I also mean using natural lighting, like outdoor light. If you're taking photos indoors, think about how the light is playing with the room, and set up your subject accordingly. If I'm doing indoor head shots, and I don't have my lighting kit, I like to use a window as my light source. I get my subject to look out the window and let the natural light do it's work. The more light available for your image, the less work your sensor will have to do. I'll show you an example of two shots. One I took with a Nikon d750, and the other with an iPhone.
The photo of the man, was taken on a Nikon d750, and the photo of the cat was taken with an iPhone. As you can see, it doesn't matter what type of camera you use. As long as your composition and lighting is good, your camera will be able to produce really nice photos.
There are tons of other tips for making sure your photos turn out really well, but these are two tricks that everyone can start doing right away, and your photos will turn out a lot better because of them!
I hope this helps,