There are two aspects of design that you need to take seriously as a professional communicator. One concerns aesthetics, the other functionality.
Let's take functionality first. The chair you are sitting in was (hopefully) designed with your butt in mind. The software I'm using was designed to produce this text. What about your presentation? I'm always amazed to be often greeted with a shrug when I ask coachees what the point of their presentation is. Be clear about the purpose of your presentation - this is your core message. "Begin with the end in mind" say NLP practitioners. Nowadays software designers begin with the end-user in mind. So should you.
Next, let's take the aesthetics of communication. Look at what is hot in today's marketplace and generally there will be some presentational lessons to be learned.
For example, Nintendo's Wii is the current gaming phenomenon - it outsells its competitors two to one, depsite its inferior graphics. Why?
Because people like the look.
Shigeru Miyamoto, the creator of the Wii's revolutionary controller, outlined the rationale behind the product to Fortune magazine:
"We were losing out to the TV remote. So we thought: what kind of controller can we create that won't make people afraid to touch it?"
The Wii looks different to its competitors in that it doesn't glorify the complexity of its own technology - it conceals it. It looks so simple that a whole new generation - the over 60s - have been persuaded to try gaming for the first time.
Takeaway for you: the look of things matters. Specifically, simplicity is compelling. Simplicity, as a design principle, encourages engagement and trust. (For lawyers, this is largely counter-intuitive.)
Here's a presentation that models the kind of aesthetic I'm talking about: