Use 'your all' when you're talking about putting maximum effort into an activity or goal. I spent weeks practicing for the audition – I gave it my all.
Pro Tip 2/3
Conveys Passion
'Your all' often suggests a deep level of personal investment and emotion in an action. She played the match as if it were her last, giving her all.
Pro Tip 3/3
Not Always Literal
It can be used figuratively to encourage enthusiasm rather than indicate the absolute entirety of someone's abilities. Let's have a great rehearsal today—give your all, everyone!