Adding UI elements
To add UI elements to your board, open the UI elements panel in the left bar and click or drag it onto the board. You can also type a keyword into the search field.
You can also duplicate UI elements already on the board using copy and paste or the duplicate command (CTRL/⌘+D). ALT/OPTION+ drag will also duplicate UI elements and allow you to place them using your mouse.
Note: Full list of keyboard shortcuts here.