One of the pieces of self-editing advice several people told me, and I’ve actually used on the odd occasion, is to edit the manuscript backwards — start at the end and work your way to the beginning.
You can go paragraph by paragraph or page by page. The whole point of this is to force you to read your manuscript in a different way, which will help you catch your mistakes. Too often, when self-editing, we get caught up in the story (again) and then start to miss stuff. If you are reading the manuscript backwards, that won’t happen… much. It’s less likely if you are going paragraph by paragraph than page by page. If you’re doing chapter by chapter, than you’ll probably miss more stuff.
This was a short piece of advice, but still advice. 😛