- Buy a domain for your email and have a website; the website can just claim it's "coming soon" and look modern and promising.
- Ensure your email is personalized and targeted, and include direct propositions to how you will increase revenue or decrease cost or offer growth — something, anything — to the company. Super short cold emails don't work as well for startups in my experience.
- Address your emails to everyone relevant you can find, but surprisingly, C-level execs appear more likely to respond than lower-level people. They'll often forward your email to the most relevant person who will then feel obligated to reply and hear you out.
- Once in meetings, your advantage as an early startup is your flexibility. Know what you're capable of, and then listen well. Tell them what they want to hear as long as you're capable of building it and it's worth it to get them on board.
If you want to talk further on this, let me know and I can send you an email if you put it in your HN profile, and good luck!