It is not a good idea to start the day with coffee or black tea. These drain kidney energy, over stimulating the adrenals and it promote constipation.
According to Ayurveda: Drink a glass of room temperature water, preferably from a pure copper cup or tumbler. (Fill the cup the night before and let it sit overnight). If the water is too cold, it may provoke kapha dosha disorders such as colds, coughs and sore throat. For kapha and vata individuals it is actually better to drink hot water, but for pitta person lukewarm water is best. This water will not be absorbed but will wash the gastrointestinal track, flush the kidneys and helps with the kidneys and it helps with having a good bowel movement.