Recently, to make ends meet, I've been doing freelance formatting for a publisher. While most of the manuscripts I get I can chug out in a couple of hours, there are a few that make my job very difficult, and they could all be fixed if the authors paid attention to standard submission formatting guidelines. When I first started writing, I had a hell of a time trying to find these magical guidelines, so I'm going to post them here so someone, somewhere, might get some use out of them. Also to keep me from strangling a few otherwise talented writers.
Margins - One inch, all the way around. You're not helping anyone by providing space for the gutter or by pre-formatting your work for Createspace, Lulu, or any other press. One inch.
Spacing - Double spaced. This does NOT mean hit the "return" button at the end of every line. All that's going to do is make the formatter (me) want to beat you with a stiff loaf of pumpernickel. Seriously, just type and let that magical thing called "Word Wrap" do its thing. And for the love of Pete, don't hit a double return at the end of paragraphs. We just have to go back and delete them all. By hand.
Tabs - Use the Tab key instead of spacing over five spaces. Not every font spaces the same, and the tab goes by a unit of measurement as opposed to the random size of a particular letter.
Font - This one varies, but for the most part a monospace font (like Courier) is what's preferred. Also, twelve point is the general rule. When in doubt, and I can't stress this enough, LOOK UP THE PUBLISHER'S GUIDELINES!
Underlining/Italics - Anything that needs to be in italics in your story should be underlined, not in italics. I know, it seems weird, and I never understood it either, but here's the fact: When formatting your work, publishers, formatters, and everyone else can actually SEE the underlining, whereas the italics just kind of run in with the rest of the text. If we need to change font, we need to be able to see what has to be changed. Do our eyes a favor and underline, don't use italics. We know what to do. Honest.
Document Format - Send it in either a .doc or a .rtf file. Those two formats guarantee we can open your work.
When in Doubt - Do some digging and look up the publisher's guidelines. No matter who it is, publisher, agent or editor, they undoubtedly have their own way of doing things, and there are reasons for them. If your manuscript doesn't adhere to their guidelines, that's one more reason they can throw it in the garbage unread. Take into consideration the number of manuscripts they have to read every day, and you'll see why they'll take any opportunity to clean out the pile.
If you want to be a professional writer, BE professional. Find what gives you the best chance and use it. Don't shoot yourself in the foot before you've even gotten it in the door.