Start with why now
Name the business change that made the current website inadequate. A new audience, offer, sales motion, market position, or content operation creates very different requirements.
Find the evidence
Review analytics, search data, sales questions, support requests, form quality, customer interviews, and publishing friction. The redesign should respond to observed problems rather than internal taste alone.
Give every page a job
A sitemap is not an inventory. Each page should serve a visitor need, advance a belief, or support a task. Remove pages that exist only because the old site had them.
Prepare the organization
Decide who owns content, who approves decisions, which systems must connect, and who will run the site after launch. A website cannot compensate for unresolved ownership forever.