I have a newbie question. Let's suppose that for a sprint backlog we choose one user story from product backlog: "As a photography junky I want to be able to make a collection of favorite photos".
And then we want to add some more in-detail tasks, for instance "making a mockup" for UX-designers, "making changes to model" for backend developers and doing front-end implementation of design ideas.
So what is the best practice for that? Do we add these sub-tasks to sprint backlog, or we create separate "detailed to-do" backlog? Do we add story points to each sub-task?
With stories points it's an especially interesting problem, because if we add sub-tasks to sprint backlog we are counting tasks twice: first for user-story in general and second for it's parts in form of subtasks.