Many of us preview our posts multiple times before we are satisfied with them for public viewing. Blogger in Draft now supports a new, improved preview feature that allows you to see how your post will actually look to your readers.
On the New Post page, click on the Preview button (this is a new button that we’ve just added), and you will see a new window open with the WYSIWYG preview of the post. This is how your blog post will appear to your readers when you hit publish, with the same format and style of your current Blogger theme.
Please note that the preview page does not automatically update as the contents of the post changes. To make sure the post looks OK after you've done further editing, you can refresh the preview page manually, or click the Preview button again.