Quick Swimming Tip: Breathe in the Trough
By keeping your head down and not lifting your head too high to breathe, you can create a nice little trough in the water around your body. This will give you a higher, faster more streamlined position.
Instincts, especially in the open water and choppy conditions may lead you to turn and lift your head unnecessarily far out of the water and produce a break in your flow. Practice rolling your body from the torso to breathe and only bringing your mouth out enough to pull some air in through the side of your mouth.
See in the photo how the edge of my goggles and corner of my mouth are both at water level. If you keep your opposite ear pushed in the water and turn your head looking slightly behind you it should help keep that nice streamlined body position through the water.