I love this question. Helicopter parents especially will find letting go extremely troublesome. I feel sorry for them. Children grow, experience life, make choices, make bad and good decisions and ultimately, will live their own lives. Parents need to let their children drink from the fountain of life without interference.
I am a fortunate man. I have three grown and professional daughters. I have subscribed to the philosophy of, "We give them roots and we give them wings." The main ingredient, however, is to always love your children unconditionally.