Setting goals for your presentations greatly improves your presentation skills — but trust me, it is nothing compared to having a vision for the future. A moral vision, that is. It's not just about "what do you want", it's about "what are you standing for". Steve had a vision, he thought "computers for the rest of us" are destined to change the world — so he should be building and selling them. To me this is the main reason he was such a magnificent presenter.