“Don’t forget to ask for the results and a testimonial.”
So often we can get hung up on this and use it as an excuse to put off publishing a case study. I want to emphasize what Darian wrote in the bulk of this article: build a writing habit and write case studies as you go. Share the case study with your client when you deliver the final product to them and publish the case study in your portfolio. Publish it now, before you have any reported results from the client and before they send you any kind of testimonial. If they do get back to you, edit in any additional information or praise from the client that will strengthen your case study. But if they don’t, you still have a valuable case study strengthening your portfolio!