I feel coaches should work with the student to find what they are having the most difficulty with in their poker game and work out a plan to try and achieve all of the students goals.  I think another key thing is establishing early in the coaching/student relationship how the student learns the most.  For instance I try and do a HH review of a student for the first lesson where they send it to me I go over it on my own and write the hand # and comments or questions I have.  Send it back to the student and they can then respond with any questions about the hands that I wrote something on.  Then I do a HH review but over skype and mikogo and go through it with them and talk over hands while going through it as it's the first time I've seen the HH and I can tell them what I would do before it actually happens in the replayer.  Then I like to do a live sweat of either them watching me play and asking questions or vice versa.  After doing these I leave it up to the student for which method they learned the most from and we try and continue on that path until they can achieve their goals.

As far as selecting a coach, it also depends on your goals and where you are at in your poker game.  Make sure you are comfortable with whomever you pick and get the most out of it.  Just like ttwist if you have any questions feel free to PM me.