Possible Clues:

• "Get a move on!"
• How to get there with injured foot? Hurry
• 'Get going!'
• "Get going!"
• 'Hurry up!'
• Get moving
• "Get busy!"
• "Get busy on that!"
• 'Get going!,' and a hint for the starts of 17-, 24-, 51- and 62-Across
• Get started