Yep that is how it works. Don't have a reference to hand at the mo. Once ATC have cleared you to the IAF then making any intermediate step/check altitudes, config changes, speeds and terrain avoidance are all down to you. A good example would be the ILS onto R13 at LEMG. ATC will clear you to either a FL or altitude and clear you for the approach. There is significant terrain on the approach and hence a stepped descent until the latter stages where you pick up the glide. We would arm the localiser and lock onto that about 25nm out or so and then step descend to the final platform altitude before arming the glideslope to ensure terrain clearance.