Half the battle is your descent planning.
Keep in mind that 3 x your required height change in thousands of feet will be the track miles you need to descend, and 5 x your groundspeed is the rate of descent you need. So if you are at 35,000 feet with a ground speed of 360 knots, you will need 105 miles at 1,800 ft/min. Remember though, you will need an extra 5-10 miles to slow down too. Keep an eye on the wind on the way down, because obviously it can change, requiring a different rate of descent.
Put in F speed and the ILS platform height as a constraint in the flight plan at the point where you expect to capture the glide, and put in the descent winds all the way down. The aircraft will work everything out (but mentally cross check it as above), and will give you a realistic top of descent point at which to request descent from ATC. This will mean that you will be in the right ballpark on initial approach in terms of energy control without having to grab handfuls of speed brake, or even the gear, to slow down and go down. Of course, the actual descent profile will be largely what ATC give you, and they may still ask you to 'slow down and go down', but if you've asked for descent in good time, and got the speed under control, you will be better placed to accommodate ATC.
The key to a stablised approach is speed and energy control. If you come screaming down the ILS, your engines will be at idle at 1,000, because you will still be trying to slow down - this could lead to an unstable approach and you will have to go around. Aim to take 'flap1', (i.e. the slats), at around 15 track miles out until you get comfortable with the energy management.
A tailwind can cause an unstable approach, and if the tailwind is too much, too low down and you're not stable at 1,000'; a go around, followed by vectors to an alternative runway will have to be used - but that won't be your fault.
Hint: If you can't do 5 x groundspeed in your head easily; simply halve your groundspeed and add a zero - it gives the same answer, e.g. G/S = 430 kts, V/S required is 2,150 ft/min.
Last edited by Uplinker; 22nd Oct 2012 at 19:31.