Head
How you hold your head is key to overall posture which determines how efficiently you run

• let your gaze guide you, look ahead naturally not at your feet
• don't allow your chin to jut out

Shoulders

Play a role in keeping your body relaxed while you run, another key to maintaining good posture

• keep them low and loose
• if you get tired do not let them creep up your neck
• keep them level, don't let them dip from side to side with each stride

Arms

Your hands control the tension of your upper body and your arm swing works with your leg stride to drive you forward

• keep hands in unclenched fist, fingers lightly touching or resting your palms
• relax your fists, imagine lightly holding a piece of paper between your thumb and second finger 
• clenching fists causes muscles to contract wasting energy
• arms should swing back and forth, not across your body
• swing arms up to chest and down to your hip
• bend elbows at about 90 degree angle floating between chest and waist 

Torso

How you hold your head and shoulders affects your torso, if you position them correctly your torso and back will naturally straighten allowing for optimal lung capacity and stride strength.

• keep torso upright, if you start to slouch take a deep breath and you'll straighten out naturally
• stretch yourself up to your full height with your back comfortably straight 

Legs/Stride

Correctly stride will help you to run fluidly instead of wasting energy while you run.

• your feet should land directly underneath your body
• as your foot hits the ground your knee should be slightly flexed so that it can bend naturally on impact
• if your lower leg extends out in front of your body your stride is too long
• leg should land underneath your body
• lift lets only as high as needed to maintain proper stride
• landing on your forefoot can strain your calf and achilles

Ankles/Feet

The part of the body that many people have the most trouble with pounding the ground and striking with your heals leads to energy loss and possible injury. 

• lean your body from your ankles without bending at the waist
• keep your ankles flexed as you push off
• flexing at the ankle reduces unnecessary muscle strain and creates more force for push-off
• most good runners land between heal and midfoot, but ideally you should land on the balls of your feet and push off 
• roll forward quickly and use your calves to propel you forward with each step
• your foot should hit the ground lightly, running is springy and quiet

And now that you're a pro...