Three reminders:

You know this business better than anyone else in the world. Because of that fact, there’s nothing to really memorize or fret about. All of the facts already live inside you – you know them like the back of your hand – so now you’re voicing them to a bunch of curious people.
The audience’s minds will be only half-present (as they will be thinking about how the product applies to their lives and how they would think about this investment), and they have no idea what you’re supposed to say.
Minor mistakes won’t register to anyone but you, so don’t get tripped up on them. Just take mental note and weave-in missed details where you can. As long as you have memorized and hit all of your “anchor” phrases, you can rest knowing that your message was delivered.

Best practices :

Decide not only what you are going to say, but exactly HOW you will say it ;
Open with a question to the audience, humor or relevant interesting fact (to buy enough time to breathe)
Use a framework (ie. There are three things I want you to remember, we solve problem x, we are the … insert analogy to recognizable solution)