The four adaptations that I offer shooters for one-handed shooting are:
1. Match the shooting hand with a same-side leading foot (e.g. left-hand-only shooting has the left foot leading).
This is a stance modification during static shooting practice; it provides for the shooting itself to borrow from boxing or epee work, if we were to liken the pistol held at a compressed high-ready to a ready lead-hand fist or an epee en garde. Significantly, it reduces the abdominal torsion that contributes to an exaggerated and diagonal\across-body recoil characteristic, as seen when one shoots with a mismatch of shooting hand and leading foot.
If transitioning from movement to static\near-static shooting, then the matched lead-foot reaches and sets in advance of the shooter extending outwards for firing, ensuring a minimum amount of forward travel has been satisfied. This may be contextualized as working near\around teammates, deconflicted no-shoots, and\or confining microterrain; such that the shooter has the opportunity to meaningfully demonstrate safe-practices for supporting fires (e.g. "don't shoot from behind teammates," "if you want to join the party, get on-line.").
2. Drive the shooting-side shoulder behind the gun, as if a lead-hand punch frozen at full-extension. (This is the range of motion involving the serratus muscle.)
Driving the shoulder forward provides for more linear alignment of the weapon, wrist, elbow, and shoulder; and reduces the lateral offset between shoulder and spine. The greater the lateral offset between shoulder and spine, the greater the turning of the shoulders under recoil; the lesser the offset, the more the recoil is received as a linear and vertical impulse, sans lateral\diagonal component. That allows for the sights to be better tracked through a narrow vertical arc of movement overall, and for the weapon to be more readily returned to the eyeline through pre-loaded isometric tension and as supported by bone support.
3. Flag the shooting-hand's thumb upwards and attempt to press the second joint or second segment through the frame and touch the trigger-finger's base-knuckle.
The support-hand thumb pressing actively into the side of the frame provides for majority opposition to the trigger-finger's pressing during two-handed firing; reducing or eliminating that trigger-finger's ability to deviate the muzzle-line prior to firing. With one-handed firing, the thumb being upcocked and pressed into the frame provides for an equivalent function, albeit with less mechanical leverage (pressure applied behind the trigger rather than afore the trigger) and with fewer muscle groups involved.
4. When shooting with an asymmetry of shooting hand and dominant eye, turn the chin towards the shooting-side sufficient to move the dominant eye behind the sights of the pistol at full extension and in accordance with the preceding three adaptations.
I expand upon the aphorism of "bring the sights to your eyes, not your eyes to your sights" into "bring the sights VERTICALLY to the plane of your eyes, and your eyes HORIZONTALLY to the eye-line." Drifting the weapon laterally to enter the eye-line can only be accomplished by moving the wrist and elbow off of the line drawn between shoulder and target, exacerbating the expression of recoil after firing. More so, it requires a bend in the wrist, reducing expressed grip strength and reducing the finer capability of the trigger finger to operate in a deliberate manner as the operative tendons are now working through the complication of a bent wrist rather than unimpeded as with a neutral wrist.
Errata:
Keep the gun upright and vertically aligned.
Eliminating articulation of the wrist and elbow are difficult sans a second hand on the gun; but reducing them remains desirable.
Both shoulders still must be forward of vertical alignment with the hips.
Recoil is ultimately grounded out through the trailing\far-side foot.