A few more that come to mind over the past week or so traveling the skies....
"Check'in wid ya on twenny one nine...." heard it (diff freq's of course) all too often. Why not just give the standard & required call? I know it sounds cool to you but others think you sound just plain unprofessional.
The correct & proper use of the word HEAVY. On first contact with the TERMINAL RADAR AREA prefix the callsign with "HEAVY". The ICAO standard is for any aircraft taking off with a gross weight of 300,000 lbs (140,000 kgs) or more to use the term "heavy" in radio communications BELOW 18,000 ft AMSL. In the US, the threshold for "heavy" is 225,001 lbs (115,700 kgs) or more. The term HEAVY may be omitted after initial contact with ATC.
As a Capt, or especially in anyone in the training department of any size operation, carrier, or airline I believe it is your / our responsibility to set the standards. (It should be bread & butter at flying schools). Where knowledge is missing employ some basic CRM and use the time in cruise when able to pull out the books! That also means that you have to allow the FO to point out a few things in your direction.... At the end of the flight I'm sure many beers will be owed to each other. Part of the fun & part of the professionalism.
As some others mentioned, there is a definite trend to some airlines and some regions. Waaaay back when I was on the receiving end of a hard-ass (but fair) Capt he commented that poor RT by the FO is a reflection on him as Capt as it is his name on the flight plan, let alone the others at your airline or operation. If ATC get the !!!!$ & wish to file a report, whose name do they see? And "we" have a preconceived collective opinion gained already be these previously mentioned regions and / or carriers by way of example.
Set a standard, not stoop down to one.