Keeping in mind that the goal of a pitch meeting is to get what you're pitching, one of the biggest challenges during the meeting may be that the person able to say yes (the decision-maker) isn't in the room.
Just for a second, let's draw a distinction between getting approval and getting buy-in, because they are different. Approval is the act of the decision-maker saying "yes, proceed with your idea". Buy-in is the act of getting someone to say "yes, I can support your idea". However, the idea hasn't been approved yet.
Getting buy-in isn't confined to senior leadership. It also includes colleagues and employees. This is especially true when the thing you're pitching could be perceived as unpleasant. Several times in my career, I've been intentionally hired to make change happen, knowing that some of the necessary change would be difficult. And how those changes are implemented defines us as a manager and leader.
To demonstrate the point about buy...