I'm not a controller but have been listening to my VHF radios for over 30 years and from what I know, if there is only one or a few aircraft arriving, usually the controller will offer a simple vector to downwind and base or straight in depending on the direction of arrival and runway in use. Most important, as long as the aircraft maintains minimum altitudes for noise abatement until established, and then stays on or above the glide slope there after, from my listening experience there is no strict adherence to following the STAR. There are many variables that could impose different procedures. Even with one arrival, there may be departures and that may require use of the STAR. I've noticed late at night when there may be only a couple of aircraft in the terminal airspace, the controller will advise the pilot to "put away their arrival charts" follow his vectors and be at a certain level at x DME, etc. IF you listen to the AMS feed early morning local, you can hear (and see live on Google Earth) what I've mentioned above. Usually its the low level Center Controller who will advise the aircraft as it begins to descend to disregard the STAR.
At what altitude do you take control of an aircraft for arrival?