If you have a nagging question about how a technique is applied or if you are doing a part of a form correctly, ask the high rank.  Traditionally, before or after class you should find the highest rank available and ask your question.  If the highest rank is busy talking with someone else or training, then find the second highest rank to ask your question to.  It goes down the line to the third highest rank and so on.  No matter how trivial or insignificant you feel the question might be – the high rank have been around for awhile and it’s their responsibility to pass on what they know to the lower rank.