I’ve noticed that pilots are forgetting to request descent via a STAR to center before beginning descent. Please note, this is required so that controllers know where exactly you are placed :)
Just a couple more pointers to keep in mind:
You don’t need to request descent via a STAR to approach
If you don’t have a filed STAR, you must request altitude change manually, but don’t start descent without permission.
Just to add on to this. It’s highly recommended one has a filed STAR wherever possible, but if not, a simple Approach request to Center would suffice, compared to manually requesting altitude changes (though neither are really wrong).
Yes, requesting an approach to center is an option as well, but I prefer if pilots just request an altitude change because the approach service that they receive mostly depends upon the approach controller present. Both ways work though.