Start by thinking about what the three or four main things you want potential investors to remember about your company or product after meeting with you. 

Then explain those three or four things as clearly and concisely (the fewer words the better) as possible before even going to your computer. 

Those three or four things have to include what makes you unique / different / better than everyone else in your defined space, and how that differentiation will lead to you making money for you and your investors. 

Then you are ready to start mapping out your investor deck on your computer, preferably not with a generic template, but instead with a deck that is designed with your branding and messaging in mind. 

Again, keep it clear and concise, not overly detailed. 12 to 15 slides is a good target. Much more than that and your messaging and your audience will tail off.

Feel free to check out some sample decks at http://ift.tt/2rkxGeK