According to Influence – The Psychology of Persuasion, it’s easier to ask someone a small favor first before asking for a bigger favor. Therefore, design a Slide that you don't necessary make money, up-sell with Essense, then finally shoot for selling your main products - the Profit Booster.
When offering the flagship buffet or speciality style of products/services, you want to build in the offers with some exclusiveness. Exclusiveness can be achieved in two ways: in scarcity or with urgency. Often time, scarcity implies urgency so you often only need to design a product with scarcity.
Products can be sold before the payment is collected. This is where pre-sale comes in to build up future sales. A typical pre-sale has five stages. See the mind map above for a quick reference.