This is a combination of Passion, Preparation and Presentation but they should be an equal 33% of the total pitch.
How many Pitches fail because there is no Passion? If you are not committed and do not believe in what you are selling why would the Buyer be interested?
Weak Preparation never wins orders or generates interest. Thinking on your feet might be exciting for you but not if you are on the receiving end f a shambolic presentation. Buyers have long memories!
Good, confident Presentation always leaves a strong impression. Practise and Practice some more until the Presentation is the best it can be. If you only have one attempt to make a good impression get the Presentation to do all the hard work for you!