Presentations can be GREAT whether or not they use slides or other visuals. Presentations can also be lousy with or without visuals.
"The good presenter grabs their minds at the beginning of the
presentation, navigates them through all the various parts, themes, and
ideas, never letting go, and then deposits them at the call to action." — Jerry Weissman
This post is a short list of key concepts to develop GREAT presentations.
1. Clarify the Goal of your presentation
What is the destination to which you will take your audience?
Get clear on what you want to accomplish. Why are you giving this presentation to this audience? What action do you want from them at the end of the talk? Agreement? Being more knowledgeable? Purchasing your product? Deciding in favor on your legal case?
Every aspect of the presentation should be relevant to what you want your audience to know, believe, or do when they walk out the door. Think of this as the Destination or The Take Home Message
Now since you have set your goal make a slide that succinctly states your Take Home Message in big block letters. Try to make it only one short sentence; Try for 10 words or less. You can also use an image to help picture the result or destination. I have used a pagoda to illustrate a destination but you could use a person signing a contract, people marching for a cause, or a jury giving the verdict you want.
Put this slide at the end of your show as you are working on the presentation. Refer to it again and again to help you stay on target.
2. Get clear on the identity of your audience.
WIIFT: What's in it for Them?
"When we are asked to share our expertise with a group who are on the
whole not specialists in our field, we have to think very hard about
what is important (for them) and what is not (again, for them). It is easier just to do the same presentation we always do, but it is
not about impressing people with the depths of our knowledge, it’s
about sharing something of lasting value.
... Good presenters try to put themselves in the shoes of the audience so to speak. ... Failing to answer the
question “Why does it matter?” — or “What’s in it for them (the
audience)?” — is often at the heart of a failed presentation."
— Garr Reynolds
The needs of different audiences differ. The jargon you can use in a presentation to your peers cannot be used at a presentation sponsored by the Chamber of Commerce or a presentation to a jury. Similarly, the actual goal of the presentation will vary. A presentation to scientific research peers and a talk at the local chamber may have the same goal of "informing or educating your audience" but the depth and breadth of the content will radically vary between the two groups.
3. Don't tell the audience EVERYTHING!!
To paraphrase Jerry Weissman "Many presenters labor under the mistaken assumption that, for their audience to understand anything, they have to be told everything."
Our brains tend to replay the steps that we, ourselves took to come to a conclusion. We naturally start storytelling in that way. However, we may have taken years to come to this point and our audience does not have that long of an attention span!! Do a Data Dump as part of your preparation not your presentation.
A Data Dump is an important step to get the information out in front of you so you can look at it all. Having it there makes it easier to see the key points.
Think of the Data Dump as being able to see the body of water that is your knowledge on the subject. Now think of the key points as the stepping stones you need to provide to lead your audience to the destination.
These stepping stones are a good visual image for this tip. They
are solid, feel safe, and the shape is known and trusted but they lead
us into waters we have never even imagined.
4. Use the KNOWN as a starting point.
People use prior knowledge to provide a foundation and/or context for new information. One of the ways we can quickly connect with our audience is to consciously create a framework for the material. The connections engage them right from the beginning and then allow them to build on those connections.
Analogies are phenomenally strong tools for exactly this reason. We used the similarity to lead people to understand the new and dissimilar.
This concept is also important when considering visuals elements. The method used to present data can enhance or detract from the comprehension. Use concepts, jargon, and methods that is familiar to the audience. The general public is familiar with simple bar graphs but not with more detailed schematics that a scientific community would quickly grasp.
5. Lead your audience to THINK but not over effort.
Thinking leads to learning and memory. Leading your audience through a
thought process to a conclusion; especially when they reach the "Aha!"
before your "Aha" slide causes more of the information to be stored in
long-term memory. 
I also think there is an "ownership" of the
information. It has been "discovered" by the audience instead of "told
to" them. I am sure there is a cognitive science explanation for that
reality too.
Leading someone to think though a concept to reach a conclusion is
radically different from leaving your audience to wallow in effort to
figure something out. The goal is to set the stepping stones step length apart more or less.
You can lose your audience by showing slides
that make them search for the meaning or add, subtract, or calculate,
etc. You can also lose your audience by have too many visual bells,
whistles, and words that distract from the main point of the slide. I call it "Visual Noise". It is hard to hear music clearly with a jack hammer pounding the concrete right outside the window. Similarly it is difficult to clearly see the point if colors are clashing and things are zipping into the slide from all directions!
6. Summarize Frequently.
Summarizing serves multiple purposes and is very beneficial. Using our destination and stepping stone analogy, think of summarizing as reconnoiter spots along the route. You allow your audience to package up the information you have presented so far and lock it into a memory location.
People remember the first and the last pieces best when given a long string of information. Summarizing a section allows the summary to be the last information.
Summarizing also reminds people of the knowledge they have gained. One of the big reasons why toddlers want to hear the same books over and over again is because of the lift they get from "knowing" and being able to "anticipate correctly" what is coming next. A summary serves the same purpose for your audience and gives the same burst of energy. The summarized section then becomes the foundation or context for the next chunk of information.
7. End with a Wrap-up!
End with a very brief review of where you started, where you ended and why it matters to your audience. Remember that people remember best what they have heard last. That is a lot of the power behind the saying "End with a Bang!"
You do not need to use the initial slide you made that states your Take Home Message but you should have clearly arrived at that destination! . . . and so had your audience!!
You should always leave time for questions. If there is a lengthy pause at the end Stephen Klosslyn has some wonderful one liners to use which usually will get conversation going:
"I hope I wasn't skating too fast on thin ice." Or the one I like best is:
"Should I be taking this as a testament to my powers of persuasion?"
8. Practice! Practice! and Practice!
If you are a beginner at presenting or if you are working to improve then your Living Room chairs (and maybe your spouse too) should be tired of hearing the talk over and over before you present it for the first time. If you are a veteran presenter your living room chairs should at least hear a new talk twice!!
And you should not be sitting in those chairs while giving the talk! If you will be standing when you present then stand when you practice. If you will be perched on a stool then perch at home. If you are in wheelchair then practice from the position you want to be in when you present.
Practice trains our body and our responses to become automatic! Steve Jobs may look smooth when he presents but he has spent hours practicing before any Keynote or any other presentation. So have the rest of the stellar presenters!
