Engineer turned B2B founder here. I've sold to a lot of large $100M+/year businesses at this point, so feel decently qualified to answer this question. The top three things that helped me:
1. Listen to yourself pitch. Ask people you talk to if it's OK to record the pitch and then listen to it repeatedly and take notes. It will be painful, and you'll notice so many things you hate, but you will get better. This is the number one thing that helped me get better.
2. Understand your customer. Really understand them. What are their hopes with buying your product? What are their fears if they make the wrong choice, or no choice at all? The stuff that's really at the core of these questions-- it's deep, personal, often embarrassing stuff people won't just tell you. Getting at this sort of thing is a skill. If you do it well, you'll not only sell better, you'll have a better sales process, and probably a better product.
3. Read Influence: The Psychology of Persuasion (https://www.goodreads.com/book/show/28815.Influence) by Robert Cialdini. If you're a former engineer, you'll especially love this book. It helps you understand how people tick, including yourself, and some of the techniques your competition are probably using.
Finally, don't be an asshole. It's so easy when you get good at sales to view the sale itself as the goal. It shouldn't be. The goal should be solving the customer's problem. Getting the sale is the first step, but make sure you only get it if you can genuinely help the customer-- if the customer will be thrilled they bought from you a month from now. The world has too many assholes willing to sell people the wrong thing for them. Don't be another one.
In all situations, you really have to look after yourself. If someone ever asks you to work without pay, they're asking you to up your risk. Demand more equity. The greater the risk, the greater a return you should get, otherwise you're making a bad investment.
Founders can be assholes. So can investors. Always look after yourself (and your team, if applicable). Too many assholes and horror stories not to be wary.
I've been both a founder and an early employee. As an early employee, I always received a salary, and knew I could leave any time I felt like it. My level of risk was low, and I was perfectly happy with my equity knowing I had a nice upside without much downside at all.
As a founder, I haven't paid myself in months, and have commitments to my customers such that I 100% can't just shut things down and leave to do something else without killing a lot of relationships and getting a terrible reputation.
Of course, I can only speak to my own experience, but I'm satisfied with my amount of equity in both situations.
1. Listen to yourself pitch. Ask people you talk to if it's OK to record the pitch and then listen to it repeatedly and take notes. It will be painful, and you'll notice so many things you hate, but you will get better. This is the number one thing that helped me get better.
2. Understand your customer. Really understand them. What are their hopes with buying your product? What are their fears if they make the wrong choice, or no choice at all? The stuff that's really at the core of these questions-- it's deep, personal, often embarrassing stuff people won't just tell you. Getting at this sort of thing is a skill. If you do it well, you'll not only sell better, you'll have a better sales process, and probably a better product.
3. Read Influence: The Psychology of Persuasion (https://www.goodreads.com/book/show/28815.Influence) by Robert Cialdini. If you're a former engineer, you'll especially love this book. It helps you understand how people tick, including yourself, and some of the techniques your competition are probably using.
Finally, don't be an asshole. It's so easy when you get good at sales to view the sale itself as the goal. It shouldn't be. The goal should be solving the customer's problem. Getting the sale is the first step, but make sure you only get it if you can genuinely help the customer-- if the customer will be thrilled they bought from you a month from now. The world has too many assholes willing to sell people the wrong thing for them. Don't be another one.