01 / Research
Find the desire. Then find the evidence.
A good ad doesn't invent a desire. It finds one that's already there and proves it's real. So research comes first, and it comes from your customers, not a brainstorm.
Where I look: your reviews and your competitors' reviews (Trustpilot, Amazon, the brand sites), your competitors' longest-running ads, Reddit and Mumsnet threads, and the organic content and comments on Instagram and Facebook. What people with the same problem are struggling with, what they want, and how aware they already are.
All of it goes into a foundational doc for your brand: avatars, pains, desires, objections, awareness level, and the claims your market is tired of hearing. Every concept is built from that doc.