I used to look at fish-eye sketches and wonder how can those ever be drawn. I always thought they were very difficult drawings to do. But when I first came across a tutorial about 5-Point Perspective Drawing from the deviantART website, I realized it isn't difficult at all! In fact once you understand the principle behind the lines, creating one is just limited by one's ability to imagine.
First 5-Point Perspective attempt. Drew an imaginary city front.
Decided to color it eventually. Completed on my iPad with Sketchbook Pro.