I've learned how to split my terminal windows with apple-d and apple-shift-d. Its very useful.
How do I then switch between the two panes (see below) using the keyboard?
I know I can use the mouse but would like to know if there's a key combo to do it.
⌘+⌥+←/↑/→/↓ will let you navigate split panes in the direction of the arrow, i.e. when using ⌘+D to split panes vertically, ⌘+⌥+← and ⌘+⌥+→ will let you switch between the panes.
Note: ⌥ is the [alt] key