Don't count your chickens before they're hatched. Don't cry over spilt milk. Don't judge a book by its cover. Don't throw the baby out with the bath water. Early to bed and early to rise makes a man healthy, wealthy and wise.
Every cloud has a silver lining.
God helps those who help themselves. Half a loaf is better than no bread. He who laughs last laughs longest. People in glass house shouldn't throw stones. Make hay while the sun shines.