Let me give you guys an English lesson. There are several people who come to mind (and I've done this, once, and realized later just how wrong it actually is) when I think about this problem. It is something that can truly make or break your story.

Using the exclamation point (!) outside of dialogue.

NO.

Let me go into more detail:

Suddenly, there was an explosion from behind!

Out of nowhere, an explosion came from behind them, knocking the group off their feet and sending them tumbling forward.

Which one helped you picture the severity of the explosion? Both, I'm sure. But which one doesn't sound like it was written by a twelve year old?

But wait! You cry. You used totally different language to make one sound less mature than the other!

That I did, but for very good reason. You see, when you use an exclamation point like example one, it looks incredibly unprofessional. Sure, it might convey the same intensity if the sentence with less words, but that is also being just plain lazy.

You do not need, nor will ever need, an exclamation point outside of dialogue to convey the severity or intensity of the situation. If you will notice, professional writers don't use exclamation points outside of dialogue (and I mean internal and external dialogue as well). If they want to tell you how bad the explosion was, they will describe it for you.

Italics make things seem just as important as an exclamation point, but allows you to emphasize one or two words that hold significant meaning which that sentence is built around.

OR YOU CAN USE ALL CAPS TO CONVEY SHOUTING, BUT THIS IS ALSO CONSIDERED LESS PROFESSIONAL THAT USING ITALICS, OR EVEN BOLD WORDS.

Bold words usually mean that someone important is talking, usually with telepathy.

Noah. God said. You have forty days to build this ark. Chop chop!

That was internal dialogue so you can't yell at me for using the exclamation point.

Do you use exclamation points in research papers? You don't (or at least you shouldn't be, unless you want your reader to assume that you're twelve), and so you shouldn't use exclamation points in a book as well. Readers won't take your book seriously if you have exclamation points everywhere outside of dialogue.

Doesn't this whole column seem professional, and don't I at least sound like I know what I'm talking about? If I used exclamation points every so often, I wouldn't sound so professional now would I?!

So please, reserve exclamation points for dialogue only. I can't take you or anyone else seriously if you use exclamation points outside of dialogue. I can't. And most other people, especially adults when you get older, won't either.