A great way to improve your photography is to buy a prime lens. Primes (fixed focal length lenses that don’t zoom) force you to move around to fit things into the frame, rather than just stand where you are and zoom in or out. Moving around is key to getting a great shot, and the more you do so, the more you will discover great new angles and ideas.
Being simpler to construct, primes also offer better performance at any given price, both in terms of sharpness, and how they render out of focus elements (bokeh). Primes also tend to be faster (larger maximum aperture), enabling you to get creative by throwing the background out of focus.
The pic on this page was taken with a 50mm prime lens at F1.4. A simple idea photographing myself in a mirror, focussing on the camera and throwing myself out of focus.
Hold on! If that was taken in a mirror, how come the camera name is not back-to-front?! Answer: I remembered to flip the image horizontally in Photoshop.