Here is what I do :-

first, check the throttle butterfly closes completely initially when twist grip closed. You want a little flex in the cable when it is shut down to ensure it is pushing a little. 

When bike is warm,

Adjust tickover with throttle stop screw to a comfortable rate with the ignition on full advance. 
 adjust the idle screw to the point of fastest tickover. You really need to turn a couple of clicks and listen for a few seconds to let it settle. When about right you should be able to clearly here a slight change/drop in motor speed if you go a couple of clicks in either direction.

Then set tickover with throttle stop screw back to a nice steady beat, probably around 1200 rpm, not too slow.

Now go to main jet. Blip the throttleand the motor should rev freely.wind main jet needle in a couple of clicks at a time, letting it settle for a couple of seconds in between twisting the throttle. When the motor doesn,t rev freely, ie stutters, thats too lean, so go back until it doesn,t stutter. Rule of thumb is 4 clicks out from there.

now try going the other way, until it stutters again as a check, as it will also bog down when way too rich. There may be quite a range between too lean and too rich.

As a check to see if you have it close, fully retard ignition. The beat of the motor should now slow down to a nice crisp metronomic pulse. Motor will get very hot if run retarded for long.
Now recheck idle, then recheck main, go for a ride, see how it goes. It may take a while, and if everything is good, you may need a slight adjustment acording to weather etc.A damp misty day will do wonders for the motor, bags of extra torque, you may need to richen slightly. If you generally live and ride at a moderate altitude, and take the bike to the beach, you will need to richen it way up, so get used to checking and adjusting even if it all seems good.

Handy to record number of clicks on needles so you can always go back there. i often pull over to the side of the road somewhere qiet and concentrate on the beat, repeating above procedure slightly during a ride.It should be possible to obtain a sweet spot within a click or two either way if everything is in good shape.

readjust cable so it is still giving a slight push/ flex when twist grip closed.

If you cannot get the bike to idle down, you probably have an air leak somewhere, usually manifold or worn throttle butterfly shaft, and so are having to run too rich to compensate.

Let me know if this makes sense and works, happy to know what other people do. I know this is not exactly how the manuals recommend to do it. Initial settings often way off what books recommend too, depends how worn everything is. 

I have a tendency to leave bikes a touch rich, an old friend of mine long since passed, sadly, always used to laugh and slightly lean out my idle whenever we went for a ride, a small fraction giving a crisp clear exhaust note as opposed to a slight farty sound, usually  a slightly better top end performance with standard cams, but often with a loss of low down torque.  Another friend of mine ate thru a piston by leaning out his harley 45 two clicks on a long run to try and beat his record for fuel economy.