Every single page on your site - not just the homepage - should have enough "above the fold" to grab the attention of your visitor. Above the fold in this case means that all the important content can be seen without scrolling or resizing the browser window. Be advised that many of your clients won't have big screens.

My server logs tell me that about half my visitors use mobile devices. Unfortunately my own site works very poorly for them so I am tinkering with improvements.

Ask for the sale - this is known as a "Call To Action" in the advertising business. The reason junk mail says "Buy Now! Don't Delay!" is that it really works; without that call to action, even if the recipient reads the direct mail piece, it might not actually occur to them to make an actual purchase.

In the case of a consultant, on every single page provide your email and phone number. You might want to use a screening service as was once provided by LinxConnect. They're out of business now; other than setting up my own asterix server, I don't know how to do that.

Read Jakob Nielsen's "Homepage Usability: 100 Websites Deconstructed" (not sure of the exact title).