How do I put a bunch of uncommitted changes aside while working on something else

If I have a bunch of uncommitted changes and want to set it aside while working on something else instead, and then later (f.i. after several days) come back to it and proceed working. What would be the easiest workflow to accomplish this? (So far I have only experience with Mercurial's basic functionality). My usual method was to create a new branch using clone, but there might be better ways.