I've just been out for a lunchtime dogwalk and saw several people out for a lunchtime run. What did I notice about their running - that they had all developed habits that affected their running, some good & some bad. The first person who ran past me had his head tilted to one side quite severely probably around 5 degrees, the second person I saw was putting a lot of effort into his running and pulling his head right back, I next saw two people running together with contrasting running styles, one ran using most of his foot with a small amount of heel strike the other ran so lightly on the balls of his feet with minimal effort.
All of the habits developed apart from the guy who was running lightly on the balls of his feet will be affecting their running performance and may in the long term result in some form of injury.
To find out more about your running habits & good technique see discover the art of running