The chin is a difficult area and many of the passes are advanced moves. Always stretch the skin first then you can go straight down and around, come from the sides inwards or at an angle and do the S-N pass against the grain. As far as the throat goes you will be limited by the type of symmetry you have to that area. Some can only go N-S and S-N and some can use more of an oblique angle while some can go E-W or W-E. You just have to try everything.