Weed out what doesn't belong.  All vegetable garden references aside, it's very important to go through your story and weed out the parts that aren't important.  This can be discussed on two different scales.  Weeding on the larger scale is about discarding the parts that have no relevance to your story.  They may be the best prose you've ever written but I'm sorry, they have to go.  This applies to redundant parts too.  Ask yourself, have I already answered this question or described this part of the character?  If so, say goodbye to it.   

Weeding on the smaller scale includes a few basics and some pet peeves.  First, it's OK to leave out the specific mechanics of your character as they move throughout the story.  I'm referring to the exact details of something as mundane as walking out of the room as illustrated with the following: 

When she saw him pull into the driveway she turned away from the window and hurried across the room.  When she got to the door she grabbed the doorknob and gave it a hard turn, then pulled  the door open so hard it hit the wall with a loud thud, rattling the small figurines on her  bureau.  Then she stepped through the doorway into the hall and raced down the hallway towards the front door...blah blah blah.

As a reader I don't need to have it broken down for me. It's OK to just tell me she ran out of the room and  went outside to meet her mystery visitor before he got out of his car.  It keeps the story moving forward and allows the reader to fill in the blanks.  Remember, readers like filling in the blanks.  We're funny in that way.

Another part of weeding (pet peeve alert) is to discard redundant words...especially those descriptive oddities that stand out from the rest of the story.  Give unusual words a cameo appearance and let them go back to the shelf at the word warehouse in your mind.  For example, a word like "multitudinous"...(admit it, you love that word)...sticks out like a sore thumb, so don't wear it out.  Another example—the word "tumescent."   Great word.  Don't kill it.  There are plenty of other words, so don't be afraid to give that old thesaurus a workout.  By the way, the next time you run into Stephen King, don't mention the thesaurus. He's not a big fan. 

The last weeding chore is delegated to punctuation.  Specifically...exclamation points.  Every writer makes this mistake at some [early] part of their career.  In an early draft of a chapter book I removed 268 exclamation marks.  You should too, and for good reason.  First off, your story doesn't need them.  Secondly, they'll drive your reader crazy.  Lastly, and this is huge, there are much more interesting ways to infer emotion.  Interesting for you the writer and interesting for the reader.  When it comes to exclamation marks, I avoid them like the chatty mailman and his multitudinous complaints about the neighbors.

See what I did there?  Looks like I have some weeding to do.