Spinning and spinning again. In the long run you can achieve move by spinning than pushing. However, it is also very important to know the correct spinning motion so that you use your muscles efficiently. You have to become a "foot-floater". On the back side of the stroke your foot should look like you are pulling it out of mud. On the top part of your stroke, move your foot to 90 degrees as if you are pushing it down again. It is hard to do this at first especially if you have some other habits already. Practice it while you are moving slowly or uphill.

Pushing is fine sometimes especially if you are trying to chase someone, pass someone, start an attack, or simply lose weight.