The coach who taught Sheryl Sandberg to communicate better explains how to give a better presentation

The best writing advice I've ever received was actually a suitcase-packing strategy from my most well-traveled friend:

"Lay out everything you want to take with you. Then cut it in half."

It's a brilliant tip, of course, but using it - as a traveler or as a writer - is an absolutely horrifying experience. Leave behind my beach sandals? Cut that paragraph about my mom? I couldn't possibly!

You could.

As Bill McGowan says, "Don't fall so deeply in love with your own content that you can't see that some of it is excess."

McGowan is an Emmy Award-winning journalist turned communications coach, whose trainees include Sheryl Sandberg and Jack Welch.

In 2014, McGowan and Alisa Bowman published "Pitch Perfect: How to Say it Right the First Time, Every Time," in which they teach readers how to communicate more effectively in any circumstance.

In one chapter, the authors advise readers how to boil down a presentation to its most essential elements. The trick? Keep your catchy opening and closing and shrink the middle section.

The beginning of your presentation should be well rehearsed - the authors say that's when you'll be most nervous, and starting off with a bang will help you build confidence. Same goes for the closing: "It should be a definitive destination you're driving to with a sense of purpose."

But the authors write: "The middle of your presentation, however, should be expandable or collapsible, so it can grow or shrink, depending on time constraints and how your audience is receiving it."

In the book, McGowan recalls that he was once asked to cut an hour-long talk in half - 10 minutes before he was scheduled to give the presentation. So he removed 12 of the 30 slides in the middle of the talk.

Once you cut some of the content from the middle, you'll have to devise segues that connect each point. You should also make sure that the shorter talk still builds up to the same conclusion.

Ultimately, your presentation will probably be stronger without the extra information. If anyone wants to know more, they can always follow up.

McGowan writes: "Rarely do I come across a client's presentation that isn't improved by cutting it by about 25 percent."