I haven't drawn in years and my handwriting is atrocious. Paper, whiteboards, graph paper, nothing saves my handwriting.
So, sketching was a bit daunting. I didn't really know where to start. I looked through blogs and blogs for some tips on getting started. or how to do this at all. I came across an article from Smashing Magazine on the messy art of UX sketching. Some quick tips: start by sketching random lines as a warm up on a scrap sheet of paper, use your entire arm/shoulder, rotate the page, start with a basic sketch and then go back and add more lines.
Sketching is about learning. It's a brainstorming exercise. They give new insights. For example, originally I thought I wanted to add some sort of coordination piece to my app - similar to Doodle but more integrated in the travel booking experience. After designing the booking tab, I wasn't sure if the coordination part would be too cluttered or useful.
From another Smashing Magazine article:
“Pictures can represent complex concepts and summarize vast sets of information in ways that are easy for us to see and understand, they are useful for clarifying and resolving problems of all sorts.”