Do you think of this as a sales call? As an attempt to convey your enthusiasm for an idea to a potential investor? Do you use most or all of your meeting time in "persuasive" mode?
If so, you are in the vast majority of people who present business concepts and plans.
The implication is that you expect the investor to react to your idea, and while that is a required entry level conversation, what follows is really where the initial judgment begins to be established.
After a few minutes of presenting your venture, be prepared to discuss the interests of the investor, aside from the product idea.
I'd suggest starting with risk assessment. The canny angel wants to understand where the big risks are and how much time and money it will take to ameliorate them. They will think about who may be the next investor in this business, if one is needed, and what risks that next investor will be happy to see solved, so that they can pay a higher price for the stock. This is a discussion between potential partners and it engages the angel pretty quickly on the topic of "how can I be of assistance?" It gets both people on the same side of the table.
The elephant in the room, of course, is the entrepreneur herself. Evidence of how you have high integrity, a background that lends itself to this venture, a commitment to the enterprise, and a willingness to align your interests with the investors, are the deal makers. Be proactive and address them rather than wait to be asked. Supply detail about your history, your advisors, and your previous employment.
Go lightly on the 5 year projections. And, I'd avoid anything like a table showing 50% annual returns and the like. Everyone assumes these are guesses.
Of course, one place to understand how well you understand your business is walking through the expense and revenue assumptions with you. More on that tomorrow.
Do let me know if this is helpful and what else you'd like to hear on this - or other - topics.