You can't.
And if you think you can, that means you never gave 100% in the first place, because if you did, then you wouldn't need to worry about saying you will give another 10%, because you have done your best already which would indicate 100%.
If you think you are gonna give 110%, why not 150% ?? Why not 1,000,000% ??
I wouldn't trust someone who claimed they would do something for me 110%.
So before you hit someone with that 110% bullshit the next time, have a think about it...
