Selling online? What are your most useful sales funnel features?

While many sales funnel builder software allow you to do many things including:

+Create landing pages
+Create membership sites
+Run a webinar event

...and more.

[Funneljoy (https://funneljoy.com) even lets you import other pages you like, and edit to your taste.]

We've been wondering, what are your most useful features while building a sales funnel?

Or even better, what new features would you find very useful that isn't already implemented?