Calling ko.applyBindings once (per root)

I can't tell you how many times I've come across questions on Stack Overflow regarding problems that come from developers calling ko.applyBindings multiple times, thinking that it is responsible for syncing the DOM and the observable data. This is more of a warning than a best practice, but I would feel remiss if I left it out entirely. For any given root element in your HTML, you should have one call to ko.applyBindings at most.