I use the FMS and program in a 4 degree descent angle. This usually results in a flight idle descent (or darn close). Then I just back it up with mental math (because the 386 computers take a minute to figure it out). Granted, you might have to use spoilers (esp. if there is a speed limitation at the fix), but that's why they are installed. Right?

A couple of problems - 1)As someone else stated, its not as comfortable for the passengers. But then again, fuel savings is more likely to save my job. 2) I think that ATC computers are programmed at 3 degree descent rates. Controllers seem to get a little nervous when its a minute or two past when they figure the descent should start. However, pilot's discretion usually works (unless you are in the Northeast US).

My $0.02.