If I want to step OP on step 3 of a feather, how do I ensure I step in the correct position ie to my left of her RF, do I

(A) Somehow move the lady to one side in preparation for it so I am now stepping outside

(B)Rotate my hip line clockwise about 1/8 of a turn so that the line of the swing of my step shifs laterally and also results in a change in foot alignment

(C)Rotate my upper body with no turn in the hip line and no change in alignment

What do you guys think ?

I'll put myself in the line of fire and say 'B'.

I'd go for 'D'

If we have developed the correct matching side leads on the preceding step, with the usual 'preparing to step OP' setup, then I am already going where I need to go, and I just take one more step, taking me OP. CBM takes care of coming back into line on the follow.

Well I was going to have a (D) but I thought it might be too leading.

My (D) was rotation of the upper body to have that face LOD with a slight knock on effect on the hips and feet pulling the (foot) alignment just past the stated DC (but not enough to register in the technique books, and with movement directed towards DC. (All implemented on 1 of course).

How does that sound ? Telemark: is that what you mean by CBM, and usual preparation/side leads etc.

What I am trying to do is to pinpoint the key factor that ensures the RF goes naturally on one side of the lady's LF, and not the other, and not on top of it. The small rotation in the feet away from stated alignment, and the shift in the line of swing owing to the slight hip rotation, would both result in rather small shifts in where the feet end up , but possibly enough given the foot-width precision required ?

Yes and No.

It's an interesting figure, and one I think very difficult to start a dance with (unless you dance a preparation step).

My preference, at start, is to take a RF side step over counts 123 of the bar that precedes the first phrase after the intro, and to swing the LF fwd on count 4 (Q) with quite strong contrary body movement (the forward swing of the R side with the LF, so that when I take the first step of the Feather on RF, I can get quite a marked swing of the L side into step 2, developing the CBM of Step 1 into the side lead of Step 2, and continue to develop that lead into the OP step 3. Now as long as I maintain that line, I come outside on 3 with no real effort, the key being the correct placement of step 2. As Howard says: "Preparing to Step Outside Partner - This is a step taken forward in a slightly more open position than a normal step, eg step 2 of a Feather Step ..."

So it's a question of careful foot placement, really. If I start the turn to the L (typically into a Reverse Turn) as I swing down into the HT of the R. Turn, my R side takes both of us around the turn. All lady has to do is to concentrate on drawing back her trailing foot neatly, and effecting a weight change with rise. She relies on my lead for the turn, and steps forward perfectly aligned with me (no danger of over rotation), and off I go backwards out of the turn. The anticipation of the turn in the foot in the rotation of the upper body down to the hips between the last step of the Feather and the first of the R. Turn brings me into line with lady (who just keeps going straight back), and I swing around her very easily.

Not very easy to describe - easier to do...

I agree with telemark.
I would add one thing i think is important. As the man, it's essential to keep the right side well stretched on step 2 of the feather, otherwise it's very easy to 'fall in' to the lady, and that's where the following right foot placement on 3 can be a problem (not to mention balance).
Also, the lady must be very careful to track her right foot (in CBMP) on step 2.

"Also, the lady must be very careful to track her right foot (in CBMP) on step 2."

This must be a typo, because the lady's step 2 is taken with a side lead on the same side of the body as the moving foot, which is the inverse possibility from CBMP.

That same direction in the body will become CBMP on step 3 when the moving foot is on the non-leading side of the body.

You're right. I was careless.

There is on this site a computer image of a couple stepping outside partner with instructions. It is possible to see that the person going forward does not step off line, and that both feet are pointing in the direction of travell. That includes the knees. You will notice that both couples are facing each other and are not turning away.Looking at the images, who is the one one that clears a path for the other. Incidentaly this is all Bronze Medal stuff.