Use pinning to stick a few cards to the right-hand side of your screen while browsing your notes.
You can pin / unpin cards to the right-hand side in multiple ways:
Pin button in the card's options
Alt + Clicking the card title
Alt + Space on a focused card
Drag and Drop card titles onto the open pinned pane (you cannot unpin cards via drag and drop!)
Edit Noteboard & Pinned cards at the same time!
One of the best use cases for Pinning is the ability to edit a card in the Noteboard at the same time as editing one in the Pinned pane, like the example below: