While most photographers are inherently creative people, I think a person can still learn to be creative, especially when taking photographs.
The biggest composition issue I constantly see is poor framing of the subject. One of the simplest yet tricky to grasp concepts of photography is what is called Rule of Thirds. Properly framing your subjects can exponentially (I’m not exaggerating) improve the composition of your photos.
I’ve included an illustration above.
In a nutshell
If you mentally divide your photo into a three-column, three-row grid, your subject or whatever you want to photograph should intersect one of those points. This makes your photo visually balanced. Your eyes are naturally drawn to those four points (locations) in a photo.
That’s it.
Many DSLR cameras allow you to display this grid in their viewfinders while you take a picture.