Darren Lester, CEO of SpecifiedBy, outlines the essential components for creating effective online product pages, focusing on product names, descriptions, images, technical specifications, and calls to action (CTAs). Key recommendations include ensuring clarity and conciseness in product information, utilizing high-quality images, and providing technical details that cater to specifier needs. Additionally, integrating downloadable files, pricing information, and social proof can significantly enhance user engagement and decision-making for prospective buyers.