In practice, under VFR, UNLESS under "close control" such as in a traffic flow in or out of a busy airport, a pilot is responsible for his own separation from the traffic he follows. When "the pilots are asked to maintain the separation on their own", that is EXACTLY what they are expected to do! DO NOT expect ATC to do your job as a pilot for you!
If you are VFR, you are expected to SEE and AVOID conflicting traffic. If you are following an airplane down an approach path on a constant glidepath, simply keep that airplane between you and the runway threshold. If you maintain an excessively steep glidepath, you may cause wake problems for following airplanes ON the correct glidepath.