My question is about the different ways of half-holing notes.
How do you do it?
Notice that I’m not asking how to half-hole, but rather asking about your particular manner of doing so.
Here is my answer, starting from the Cnat (on a D flute, playing right handed):
Cnat: rolling the LH index finger away from the embouchure hole (rolling toward the foot of the instrument). Though I usually cross finger oxxxox for this note.
Bb/A#: tip of the LH 2nd finger covers the part of the hole on the opposite side of the lips.
Ab/G#: same technique as Bb
Fnat: roll RH middle finger either toward or away from the embouchure hole; normally toward the embouchure hole.
Eb: for the lower octave: RH third finger rolled toward the emouchure hole - the note is quiet and too huffy and pretty much unusable. Upper octave: same fingering with slightly better results.
I cross-finger Cnat and have never been able to get a clear Eflat, whence the one-key flutes.
For all others I roll away from the head. My old teacher always advocated straightening the finger, so lifting the part that’s away from the player. I was never able to get that to work right, but he played fully chromatic that way.
Never really thought about it before, but I sort of roll the tip of my finger off the hole a little, (i.e. less downward pressure over the entire hole) - some times backwards, sometimes to the side.
I avoid it as much as possible - completely on flute, really. So I only do it, very rarely, on whistles. I mostly play fully keyed flutes anyway and would avoid using a keyless for tunes requiring those accidentals. If pushed, I prefer to cross-finger rather than half-hole on both keyless flute and whistle if a usable cross-fingering is available.