Nice video. A reminder that when requesting approach service from a radar controller, you do not check in and then request your approach. Your first contact should be your approach request.
You can use it when you depart and are transferred to a radar controller to indicate you are going to fly your flight plan. Hence no need to check in and then request flight following. You are basically asking for the same thing twice.
On approach, you would only use this if there are two approach controllers, usually an initial approach followed by a final, and you were handed off the the next controller. They can already see the approach service requested, so only a check in is required.
Frankly, the check in followed by request is the number one pet peeve for radar controllers on expert. It makes life much harder in a busy airspace.