Follow these simple rules and make your next presentation a GREAT experience for you and your audience.  (And by the way, the better experience you have the better experience your audience will have.)
 
PREPARE:  I know you've heard and read this from me before, but that makes it no less true.  All good presenters prepare.  This means developing a presentation that's geared to the audience, with a very clear POINT in mind.  Once you know the point you want to make, you need to assess your audience and decide the best way to get that point across to them.  This is critical.  When I speak to financial people about giving great presentations I come at them from a different angle and in a different language than the angle and language I use when I'm speaking to the folks at the CT Clean Energy Fund.   Their "pictures" are different, their problems are different, they speak different languages and they speak to very different audiences, thus my approach to each must suit these differences.
 
PRACTICE:  You have to practice, and you have to practice OUT LOUD.  In your head doesn't count.  There are two great benefits to practice.  First, if you're a nervous presenter, practice will increase your familiarity with your presentation and will allow you to give it well NERVES and all.  In fact, once you hear yourself deliver your well practiced introduction with aplomb your confidence will build and your nerves will abate.  Second, as you hear yourself deliver your presentation OUT LOUD you'll uncover any weak spots, awkward language, places that need a transition, redundancies, etc well before you are in front of a live audience!  This will not only vastly improve your presentation; it will boost your self-confidence.  You will KNOW your material is sound, smooth and strong.  How great will that feel?
 
PREVIEW:  Get to the site of your presentation early.  If you're a speaker at a multi-day conference, try and get into the room where you'll be speaking the day/night before.  If that's not possible, get there at least early the day of.  For other speaking engagements I recommend getting there at least 30 minutes early and even earlier if you'll need to set up your laptop to a projector, or run your PowerPoint to make sure everything's in order.  
 
Once you've got the technical stuff taken care of, stand at the front of the room and get a good feeling for what it's going to be like to present from there.  Then sit yourself in a few different places in the audience to see what that feels like.  (That way when there are audience members in those seats you'll be able to relate to what they're seeing and hearing.)  Greet a few people as they come in.  Welcome them and introduce yourself.  They may volunteer why they've come to hear you speak, or what they're hoping to get out of your presentation.  You can refer to this, and to them, in your speech.  This makes them feel both celebrated and like celebrities.  And armed with these good feelings they will more than return the favor.  How?  Read on.

 
            Once an audience member has met you they feel they 1.) know you and, 2.) deputize themselves as your fan club.  Now when you stand up to speak you'll see them positively BEAMING at you.  They fell like they're in your "inner circle"  they're your "Peeps" and they are rooting for you to succeed.  Who couldn't use a little of that??
 
So before your next presentation, do yourself a favor.  Prepare your words in advance with your audience in mind.  Practice OUT LOUD and often.  Preview the site. Leave yourself time to set up so you can welcome your audience (aka future fans) as they arrive.  Then take a deep breath, SMILE and get ready to have a BLAST.  Yes you! You'll truly enjoy your experience and you'll be heard.