Just Give Me The Story
Okay, so how do you pitch? I wish I had the homerun answer for you.
The first thing they say you are supposed to do is give the logline. But if you do that, they immediately search for a reason to say no. I'm not saying don't have one ready. I just prefer to start with character. It's been my experience to make your main character real as fast as possible. Many times I like to start with a question to draw their attention or stop them from texting. Yes, that will happen. For instance, "Have you ever known someone with the world's worst luck?"
So then you might say how this poor girl scratches off a lottery ticket with her house key. Turns out she won ten grand. But when she scratches off the barcode, she rips a hole through the ticket and the lottery office voids the prize. So she comes home, pissed off and tired, but her key is so worn down from scratching that ticket that she can't open her door. Now you have them smiling or maybe laughing.
Then the inciting incident comes along and suddenly good luck is the spark that gets the story rolling. You want to hit the key beats, act one transition, turning points in act two, midpoint and then the climax. And yes, they actually want the ending. This shows them that you know how to structure a story. Focus on how the concept causes conflict. Don't wander into sub-characters. And try not to name too many characters in your pitch so they ask you, "Wait, who is that again?"
As far as pitching, I've seen people dress up like their characters. I've seen writers act out the parts. Most execs have heard thousands of pitches. They have seen it all. Many of them are just one pitch away from a 72 hour hold at Cedars-Sinai. They will feed off your energy. So be the one they remember for the pitch, not your costume.
Just give them your story!