Poles are handy when you are trying to extrude something, as I described earlier with rears and eyes. But when it comes to loops which define the flow of the topology it is best keep to quads and 4 edge axis, this gives a more organic and natural look. Poles should be used when these loops interact. When loops are following the same path and then split to look round different parts of the topology, at that split is where you will find E or N poles. See just below the eye, above and below the mouth and below the ear. In fact I guess if you could work and and map where all the poles are the rest of the four point flowing topology would just fall into place.