I've had the good fortune of learning things the hard way. Here are some first principles I've come across.
Share a personal story: Identify what are the key points that you want to make and try and attach a personal story. Very few things can engage like a personal story. It gives rise to an emotion in the person who is listening to you and gets them to be emotionally invested in you.
Paint a picture: Always being with the end in mind. What is the goal you are after? Personally, professionally or any other facet of your life. And let that goal not be vague. Do not say 'I want to change the world' or 'I want to create a dent in the Universe'. That sounds cool but doesn't mean anything. Let that goal be super specific. The more numbers, the better. Say 100K users or 50 employees of $5M in revenue. Once the end goal is in sight, it becomes easier to chart out the path forward.
Find good people to be around: You are the average of 5 people you spend the most amount of your time with. So, if you are still hanging out with your highschool friends partying all weekend, you might want to take a look at that. A good way to go about it is by asking this question to yourself frequently - "When was the last time you genuinely felt that you were intellectually challenged by someone?" If the answer is more than 2 days ago, do something about that. Punch above your weight. Find people who are smarter than you and hang around them.
Habits: Discipline and Habits are more powerful than you can imagine. So, ask yourself. What are the daily, weekly, monthly, personal, professional habits that you need to have to achieve your goals? Form them. It will be difficult at first but once you have them, you will turn into a formidable person.
Returns on Investment come from Scale and not Expansion: Doing one thing for one customer really well and taking that one thing to hundreds, thousands and millions will result in a lot better returns than doing multiple things for multiple customers.
Goal of Communication: Most things in life - Relationships, Projects or Businesses fail because of lack of communication. Misunderstandings and lack of clarity in setting expectations, lead to issues from where it is almost impossible to recover. This happens because most people think that the goal of communication is to say what they wanted to say. However, that is not even half true. The goal of Communication is to make sure that the other person understood what you wanted them to understand. To ensure that this happens, one should always be anxious whether all stakeholders are on the same page or not. One key thing to ensure this is to ask the other person to explain to you what they understood. If they misunderstood, clarify.
Establish Trust: If you have trust of your Customers, Team members, Investors and Stakeholders; sky is the limit to what you can achieve with that. Just because you ask for trust, you will not get it. But once you have it, you can just run with it. 2 Main things build trust. Consistency and Predictability. If your actions are consistent and predictable, people around you will always have an easier time trusting you. If they trust you, they will always prefer you over other options they have.
Wisdom is Learnt and not Taught: When people let you down, you owe it to them to let them know. Hiding disappointment breeds resentment—and sets them up to keep disappointing you. Explaining how their actions fell short of your expectations isn't unkind. It's an investment in improving the relationship.