This is for those of you who want curved edges on those ugly squares. It took me forever how to figure out how to do this when I first learned, and I now want to share the secret with you! So open a new blank, transparent layer in photoshop. Click on the selection/marquee tool and make a square with it like I have below.
Once you have that set up, now comes the fun part of curving it! So at the top go to Select » Modify » Smooth. I usually make it about 7 or 8 for a nice curve, but of course it's your personal preference depending on what you're making. This will curve your selection.
Now it's time to color it in! I used a pattern to fill mine in. So right click on the Gradient tool and change it to the fill bucket. Pick a color and fill it in, and there you have it. This is what mind looks like! I hope this tutorial helped you out and I hope you have fun experimenting with curved edges.