[johnstmich]

Go for it! – said when a great opportunity comes up, e.g. a chance to lead an
important presentation for your company

Do your best! – said to someone who faces a difficult challenge, e.g. when someone
wants to win a karaoke contest

Hang in there! – said to someone in a difficult situation who needs great strength,
patience or endurance e.g. a person half-way through a marathon who
wants to quit

I hope this helps!