Short intro paragraph to setup the case study at hand. Nothing too long and blabby. It can really just be a line or two. Perhaps, include things like who the client is, where they are from, anything like that to give context.
This is where you will concisely detail why they came to you, what they needed done and anything else that pertains the the project brief. Anything that might be insightful.
Plan of Attack
This is where you will detail what you did and how. Include all insights that would sell your abilities from the concept, to the execution.
And here we get to show the final outcome of the work done. This can be an image gallery or or a video player. However you can best provide this final deliverable.