When it comes time to edit your first draft, where should you start? Don’t begin with the sentences. You need to look at the whole structure and make the big changes first. You need a plan and that needs to begin with working out what you are actually trying to say – what the elements of your argument are.
In another fantastic post, Katherine Firth, from Research Degree Voodoo, has lots of good advice about how to make your structural changes. http://researchvoodoo.wordpress.com/2013/10/26/structural-editing-getting-your-writing-into-shape/