In honor of all the good luck the number 13 has brought me I thought I would pass on an equal quantity of advice to all you burgeoning sales geniuses. These sales presentation tips have all been gleaned from the wise minds around me and are supported by several accumulated lifetimes of experience.

1. Boy Scout It - Always be as prepared as possible with demos, marketing materials, witty comebacks and FAQ answers. The less paper you have to shuffle through to find an answer, the smarter and more capable you look.
2. Practice, Practice, Practice - You may or may not consider yourself a sales person, but like it or not you are now playing one. It's a good idea to practice the techniques you plan to use in your presentation. Get used to speaking well and warm up your voice before going in. We recommend repeating "Unique New York" or "How now brown cow" a few times to warm up the mouth and vocal cords. Other favorites include, "The tarantula enjoys a tasty piece of chewing gum" and "The arsonist has oddly shaped feet". These saying will lighten your mood and prepare you to speak clearly about your offerings.
3. Wow Them - Within the first few moments of presenting your solutions you had better have grabbed their attention or it will wander elsewhere. Prospects are like raccoons, you've only got them until something shinier comes along. Present your expertise, their needs and your solution within the first few minutes of the review.
4. Surprise Yourself - Anytime you see something unique about your product or service, particularly if the prospect points it out, be as excited as you were the first time.
   
5. Let Them Touch It - If you have a tangible solution to a problem, hardware or software, give your prospect the opportunity to use it. Give them the illusion of already owning it. Chances are they won't want to give it back.
6. Lighten Up - It is alright to be funny. In fact, humor can be a great way to disarm and identify. If you don't happen to be particularly funny in your own right, feel free to bring someone or something funny along. Just remember: No politics and no religion. Peoples concept of "funny" tends to differ extensively in those areas.
7. Look at Me When I'm Talking to You - Make eye contact. People who avoid eye contact are usually lying or trying to look at something they shouldn't. Looking someone in the eyes conveys honesty.
8. Gesticulate (aka Move your hands). Visually illustrate your points. When discussing points, count them off on your fingers or illustrate the size of savings with some kind of "so big" hand motion.
9. Paint a Picture - Get your prospect to visualize the benefits your offering. Maybe they are cozy beside a fire instead of flicking frozen tears off their face in a chilly server room. Or, maybe they are being lauded at an awards ceremony for saving the company all of that money your fantastic hand motions just implied.
10. Give Them the Wheel - Does the prospect seem tense? Worried? Irritated? Give control back to them. Humble yourself a little by appealing to their particular expertise. Set that mood.
11. Watch the Watch - Stick to your time promises. If you hit the limit you set for yourself prepare to wrap up. If you have done everything right, the prospect will ask for more time.
12. Speed Zones - Speaking quickly while presenting tends to draw people in and make them keep pace. It also makes you look smarter than the stumbling, bumbling type. Then, when you hit technical specifications and pricing, slow down. This will add a sense of importance and ensure comprehension.
13. Apples, Oranges and Kumquats - Be sure to create a clear separation between different offerings. If customers don't understand the lines between solutions, one dud might drag the whole sale to the bottom.

Feel free to add a few more in the comments.