Keep an ear open for the tenor of the frequency. It will change too, from controller to controller, so be on your toes. Going north out of Austin, Texas, for instance, I’ll often go from the professional and busy controllers with Austin Departure to the quieter military frequency at Gray Approach to the laid-back country twang of Waco Approach to the sometimes-folksy-but-almost-always-frenetic tone of Fort Worth (pronounced as though it’s one syllable, “Forwth”) Center. The same thing happens any time you’re into or out of very busy airspace, so be ready for it. Be aware too that each control center has its own culture. Pay attention. If things are crazy, be efficient. If things are laid-back and conversational, take a deep breath.