What should I plan before building a B2B site in Webflow?

Start with the buyer, not the build. Map your audiences and how they decide, then design the sitemap and decide which page types repeat — solutions, industries, case studies, integrations, resources. Anything that repeats should be a CMS Collection, not static pages. Settle your CMS model and component system before you open the Designer; that's what makes the site scale instead of needing a rebuild.