For startups with a concept, I prefer practicing customer development. Many startups struggle to pack dozens of interviews into 1- or 2-week sprints. They can't reach enough people. My direct response copywriting and multi-channel, multi-touch cold outreach experience comes in handy. We'll get multiple rounds of customer development done in a month if you follow my playbook and you'll also get preorders along the way.
For startups who've found early traction by acquiring 10 strangers as customers, I prefer focusing on writing your "no-brainer" offer and figuring out distribution. Direct marketers since Claude Hopkins have known these are the 2 biggest levers for achieving unit economics that scale and attract financiers. Team-building and operational excellence comes into play. My analytics experience comes in handy to instrument marketing, sales, and operations. You'll see what levers to pull to achieve and sustain predictable revenue.
For startups scaling up, I prefer de-risking marketing, sales, and operations and molding all 3 areas around an ideal customer journey. My creative financing methods from bootstrapping cash-hungry eCommerce companies will come in handy to keep your cost of capital low so you keep more equity. Your valuation will be the result of how you position your company for the highest multiple.