Start with the offer, not the layout
A landing page is a transaction proposal: the visitor gives you their details and gets something in return. Most underperforming pages fail because what is offered in return is vague. Request a callback, get in touch, learn more. None of those tells the visitor what they receive, so the exchange looks one sided and many people decline it.
Replace it with something specific: a price estimate for their situation, a site survey slot this week, a sample, a fifteen minute call at a time they choose, a checklist they can use today. This single change usually moves the number more than any redesign, and it takes an afternoon rather than a project.