If you need to make yourself pee for whatever reason, your easiest option is to drink a tall glass of water. Some people find that tea and coffee have a natural diuretic effect, causing you to pee faster. Fruits like watermelon and grapes, veggies like onions and bell peppers, and herbs like juniper and horsetail all act as natural diuretics, too. If you're really struggling, see your doctor and ask about the possibility of using diuretic medication.