Being In Charge, what is the best way to maintain CRM between cabin and cockpit?

Instruction video or brochure can be sent to passengers through email or via Text Messaging before boarding, Briefing Passengers in their spoken languages after boarding for better CRM between cockpit and cabin.

Follow-up customer with  phone or Survey  then analyses usesSpss program Analysis 

  Follow-up customer with  phone or Survey  then analyses uses Spss program Analysis                        

then  Put points to improve the performance of the client