I rarely shoot photos using natural light when wearing my professional hat as a commercial photographer. That being said I rarely USE additional lighting or studio setups when shooting photos for myself - my non-professional addiction. Back lit subjects can be interesting for the light can be used to expose a profile or silhouette that might otherwise be lost in more traditional front-on light. Above I shot this photo of my Bengal Cat - Zephyr - using a 300mm f/2.8 Nikkor AF-S Mark II lens (hand-held) from down the hall of my room (he didn't know I was there or shooting the photo). I liked how the light from the window created an "edge light" effect that showed off his fur and profile. Because I didn't have the super-long lens hood on my lens (300mm lenses have massive front elements and are very prone to flaring from any light source in the frame), I got a nice colorful lens flare from the window.
Sometimes you get lucky and a photo comes together - you simply need to be in the right place at the right time. Experiment with lighting in your photos. Try back lighting - or try shooting images of subjects that are back lit - and see if you like what you capture.