I think planning for the descent was overlooked in my training.
All of my primary training was in FL and even the cross countries were at relatively low altitude. I just don't think it really came up.
But in a Cirrus in the high teens I might have 15,000' or more to lose. That meant starting the descent a good 30 minutes out for a 500 fpm descent. Plan that poorly and you have to dive bomb at the end or, God forbid, bounce around in low level heat and turbulence for miles.
As a side note, nothing wrong with an even more gradual descent, at least VFR. Since drag goes up with the square of the speed increase, there's often benefit to descending more gradually - in the above example start an hour out and descend at 250 fpm. Less of a speed gain but over a longer time for a net benefit.
I recall that air racers would sometimes climb at just below cruise airspeed to the midpoint of their course, then descend at just above cruise airspeed. Overall that could result in an efficient and fast flight.
Of course, so much depends on winds aloft and aircraft efficiency at altitude. Still, worth considering.
