There are many running techniques available (POSE, Chi, Natural, etc) but there are basics that apply to all of them. These videos address the common elements to help you run longer and faster more efficiently.
Barefoot / Minimal: if you’re interested in this direction, just ease into it. An achilles tendon can only stretch up to 1/8″ over a year (max) if you’re intentional. Going from normal running shoes to minimal running shoes is often more than a 1/8″ heel-to-toe drop. But you don’t have to go barefoot to enjoy the benefits of the barefoot technique.