You can't get better at speaking without speaking. Most people tend to do the opposite because it's scary and there aren't many options to practice.
Practice beats preparation
Craft → Execution Sense
You don't get mastery by avoidance. In the absence of getting good coaching, you need to find practice arenas. Go volunteer at a non-profit working with the team... Find places where people do collaborative problem solving.
Think about the things that you do in your day-to-day that are like a pianist playing scales. What is the version of that for selling? That's rapid rapport building, asking good questions, asking follow-up questions, being willing to ask uncomfortable questions, and asking for money and then shutting up and waiting for them to answer.
I see a lot of operators who save their best behavior for executives only. And I just don't think that you're going to be able to get enough reps to actually get good at executive communication if you are only doing it with executives.
At the core is you have to actually execute and deliver great products, and you have to do it over, and over, and over again.