We often use the arrow keys to move the cursor when editing the parameters of a command.
Imagine that the target position is somewhere in the middle of the command. Pressing the arrow keys multiple times takes time, and isn't a comfortable process.
Fortunately, there is a shortcut that makes the flow easier. We just simply hold the alt key, and click the mouse at the destination position.
The following video demonstrates how I fix a typo in a command using this tip.