We've already covered lots of changes in Android N's settings menu, but one thing we didn't mention is a new Suggestions box that shows up on top of the settings but below the contextual settings (for Battery Saver or Data Saver for example).

When you first launch Android N and if you haven't activated Google Now / OK Google yet, you'll see a suggestion to go to Voice search and actions and enable it. After you start using your device, you'll start seeing other suggestions like changing the wallpaper or setting up a screen lock if you haven't already.

Left screenshot courtesy of +Francisco Franco

For now, these suggestions seem to be smart and not pester you with settings that you've already modified.