Well lemon juice and honey with warm water first thing in the morning helps.
And another one to try is:
2 tablespoons ajwain
2 tablespoons methi dana
2 tablespoons kalonji
2 tablespoons green tea
4-5 mint leaves
Boil the above with 5 cups of water and drink them thruout the day.
Phew! It's on page 21