Quick Access to Notebooks in OneNote 2016
Rather than having to click through drop downs and display screens to access your favorite notebooks in OneNote 2016, you can streamline the entire process with just a few clicks.
Open OneNote 2016 and then right click on the tab in your task bar. Your most recently opened notebooks will be listed in the pop-up menu. Click on the push-pin to the right of the notebook name and you now have access to that notebook with only two clicks while you're running OneNote.
Bonus tip - You can pin multiple notebooks to the taskbar tab if you have a few you use frequently.