I don't do that. I go to > Dashboard > Posts > All Posts > Add new and type a sentence or maybe a paragraph and click "save". That initiates the autosave and it's smooth sailing from there no matter ho many time I edit - I'm a chronic editor.
1.Create posts and pages on your own blog's dashboard.
2. When you start a new post, add the title, set it to private and then publish it. When you are done with the post edit it to update it and set it back to publish.
3. The other choice is to get and use an offline blog client such as Windows Live Writer (Windows) or Ecto (Mac) and then everything is saved on your computer and when you are done with the post, you actually publish it directly from the blog client software. See here for offline blog editors so you don't have to go through this again http://en.support.wordpress.com/xml-rpc