On an ILS or good weather non-precision approach, start configuring to be stable at 1000ft AGL. On a 737/A320 that will mean taking gear at 1500 ft latest, or 747 approx 2000 ft. This really does cut down on the noise that the neighbourhood has to suffer. If bad weather non precision approach i.e. ceiling below FAF alt, then be fully configured by descent from platform altitude so you can concentrate on the approach, and reduce the amount of variables.