I'm not a real world pilot, only a fake one, so I pose this question to those who are:

Using a generic Twin Engine GA aircraft:
Using a generic pattern that has a procedure turn and a LOM:
What speeds (Vso reference is fine) should I aim for as I approach the IAF?
As I enter the procedure turn?
Approaching the FAF?
Final approach to threshold?
general flap deployments (i.e first notch, at the turn outbound, or whatever)?

I know this is an extraordinarily general question, but there must be some rule of thumb.  I gather that real pilots fly the approach at a much higher speed than if they were just going around the circuit VFR and that the standard Vso1.3 is really only a threshold speed, at least in IFR?.  For instance I read some real world tutorial where the guy flys the Twin Comanche at 120knots all the way down and throws the flaps down at the last minute for a threshold speed of ~80knots.  Additionally, I gather from reading the manual of the wonderful DA Cheyenne that you properly approach at around 130knots, but pull it back to around 100 to actually land?  I would like to hear from several different r/l pilots, if possible, to see how they do it personally.  (its not like Microsoft is going to yank my Sim-Pilot certificate if I don't do it right, but I prefer to do it the real way)

I'm in nearly the same camp as Mobius for light GA. I fly most of the approach at cruise speed. Full approaches are a nearly a cross country in and of themselves, so it's best to setup for a cruise configuration.

When I slow down to an approach speed depends on the approach I'm flying. For approaches with lots of tight maneuvering, like many VOR approaches for small airports, I'll slow down at the Initial Approach Fix (IAF). For approaches built for jets at bigger airport, I'll wait until I'm approaching the Final Approach Fix (FAF) to slow down. Sometimes, on ILSs with miles between the FAF and the runway, I'll keep the speed up until I'm on short final.

So, for as far as a "rule-of-thumb" for approach speeds:
Light single - 90-100 KTS
Light multi - 100-120 KTS

Here's my general order of operations:
IAF - Cruise or slowing to approach speed
Procedure turn - Cruise or approach speed
FAF - Approach speed, gear down
Runway environment in sight (or short final) - Slowing to normal final approach speed, extend flaps to desired setting for landing when inside white arc.

I go the opposite direction. My instructors used to ask me why I didn't slow down more?

When doing instrument approaches with procedure turns, trying to stay inside the ten mile radius with a twin at cruise isn't logical. This is a safety issue, as that ten miles is your protection at the altitude on the approach.

I had the most trouble with NDB approaches carrying too much speed. We had one approach where we had four miles between the final approach fix and the runway, and had to lose, I forget, 1800' ? before reaching the runway. Slow down! In the 172, 90 kts as mentioned above makes it easier to time the approach. I use that as my max speed in that airplane!

BSW727 wrote on Nov 22^nd, 2009 at 8:00am:

I've had that too.  I rode right seat on a flight to O'Hare a few months ago and our cruise speed on the way down was 135 kts and we were asked to maintain 160 kts on the approach because everyone else was flying the approach at 200 kts.  We got 1 mile out and dumped all gear and flaps to get down to our final approach speed.  That was interesting.

Andy Hughes wrote on Jun 29^th, 2010 at 6:46pm:
Things have changed since 1970 - when I got my MEL.  Landings were always straightforward, no speed requirements other than be comfortably above the stall.  Takeoff, however, required blueline speed.