In the old days, valve slide tuning for me was a matter of pulling third slide out for low D, C#, and just lipping everything else. An element of Hobson's choice in this as I never had a first valve shunt until quite recently.
For one reason or other, that doesn't work for me on the Yamaha so I've had to learn a whole lot of new stuff. I don't mind saying that it's given me some real grief since for me at least it seems to be a really unforgiving instrument for off-centre notes. But get it right and the sound is...well let's not get hyperbolic...more than okay
I can't for the life of me move two slides accurately at the same time, so I've ended up with this strategy:
Combination 1-2: kick out 1st slide a quarter inch(ish).
Combination 1-3: kick out 1st slide a half inch(ish).
Combination 2-3: sometimes a smidgeon on 3rd for G#, D#.
Combination 1-2-3: give 3rd as much as it needs subject to where 1st is currently sat.
I've tried doing the last of these on 1st as well but the slide threatens to come off on low Db (the worst note of the lot).
This seems to work pretty well on A major which historically was one of my most awkward keys for tuning. Maybe some little tweaks and adjustments to be found in other keys.
How does this compare with others (especially the Xeno players)?