Mouth
You should place your mouth on the end of the flute as if you were using a straw. Try to partially cover the hole with your top lip. This will give you better control over the amount of air/breath which is entering the flute. In doing so you will be able to slow down the rate of air which is entering the flute. This will help conserve some of your breath and allow you to play for longer before needing to take your next breath.