How do CFIs typically determine proficiency for complex and high-performance endorsement? I'm working on getting checked out in our flying club's Arrow II. Our club's insurance requires 10 hours of instruction if you don't have any retractible time. 

I've done a few hours with an instructor, and he signed off on my complex endorsement, which I also need from an FAA standpoint. So I'm FAA endorsed, but I need more time to satisfy club insurance.

§61.31.(d)(2)(e)(i) says:


  (i) Received and logged ground and flight training from an authorized instructor in a complex airplane, or in a flight simulator or flight training device that is representative of a complex airplane, and has been found proficient in the operation and systems of the airplane;


What defines "found proficient?" What is the list of things an instructor "ticks off" their list to be able to give that endorsement?

Same question for the high-performance endorsement?
This Advisory Circular describes what should be examined when transitioning (and ultimately endorsing) a pilot for complex operations. 


  This publication is offered as a guide to the procedures and standards
  to be followed for a thorough and comprehensive checkout in these
  airplanes. The conscientious application and adherence to the scope of
  coverage recommended in the syllabus should result in a more
  competent, effective, and efficient pilot.


The document is fairly short and I suggest you look through it, for brevity I wont copy it here as its pretty much all relevant. Its important to note that this is simply what the FAA suggests (albeit strongly) and its not required all the described things be covered in a checkout. Although the instructor may be assuming some liability by signing you off without a proper checkout.