Here's a brief look at how I create my symmetricals in photoshop! It used to take me days (sometimes weeks) to draw these by hand, but photoshop speeds up the process a lot! Don't get me wrong, each stage is several hours worth of work, but it's still faster. It's also harder in some ways. For instance, when working by hand, it was important to focus on the image as a whole so that one area didn't get so ahead of the rest that repeating the pattern was almost impossible. Digitally, I can work in section and then copy it and then manually detail each section. But working in sections that way means that you can't directly see what you're doing. You have to wait until it's all been added. I think, really, both of these approaches has their benefits and challenges, and I'm still exploring what I can do with it all!