When you realise you’ve made a mistake, take immediate steps to correct it. Don’t let your pride get in the way of taking those steps. Apologise, taking full responsibility. That will speak for your character more strongly than the action of making the mistake in the first place.
Source: Dalai Lama’s 18 Rules for Living Expanded @ High Existence
Photo: I'm Sorry by Leyram Odacrem under Creative Commons license