In an attempt to get better with keyboard shortcuts on Ubuntu I've - for the time being - ditched the mouse. I generally only use two applications, Firefox and Terminal.
Opening a new terminal is as easy as:
Ctrl + Shift + T
It starts rather small but I resize it by using left or right with the Super (window/apple/command) key.
Super + Left Super + Right
Then its resized to either the left half of the screen or the right half of the screen.