When I changed my running style, I was given all the tips here, and they're certainly right, but it's a lot to think about when you're running. It didn't click for me until I concentrated on just two things...running more upright, so that my foot strike was almost directly underneath me, and upping my cadence to force myself to take very short steps. I was given the recommendation to strive for 180 strides per minute, so when I was relearning to run, I basically counted out a waltz beat in my head, 1-2-3, 1-2-3, ... Do that roughly once per second and keep your feet moving at that pace and it becomes hard to do it wrong.

Oddly enough, I expected that running with that cadence would fatigue me much faster, but midway through my first run, I found myself being less fatigued than my previous technique.

If all else fails, bend the knees and go down few cm. Then try to kick you butt with the heel going up. This will naturally lean you forward and your striking leg won't heel in first on the next strike.

Also, try to keep your head in the same virtual horizontal line. Head/torso going up and down can cost up to 40% more energy.

For extra points, your torso shouldn't be swaying, arms moving should be enough.

YouTube marathon runners for Olympics and look at some training videos for in depth info.

Simple: observe a kid running before he gets used to padded shoes. That's the natural way of running and is similar to experienced runners.

In my experience, here are the things to be actively controlling: don't hunch over (keep your back relatively straight), keep your arms bent at 90 degrees and swing them moderately (not too little, not too much), don't lock out knees, don't heel strike (strike with the blade or ball of your foot, whichever you prefer). If you're swaying side to side, you may need to place your feet closer to the centerline of your body. Everything else should come naturally.

"Barefoot" or "Regular"?

They process is entirely different.