I don't propose my method will work for every gun or every hand but if it can help just one person my post has been worthwhile. Keep in mind that my hands are on the small side of average and the guns I shoot are the type that have small grip frames. If your hand is large or the gun has a larger frame the technique may work for you but some alteration may be required. Popular guns like the Ruger Vaqueros and Ruger Bisley Vaqueros are too large for me to use this technique, but it may work for you.
The technique I use is the side-sweep cocking method.
The hold is as high as possible up the handle, to still allow hammer clearance, with elbow bent slightly and wrist rolled down into the locked position. Height of POA is altered by moving the gun closer or further from eye. It is important to have the little finger on the handle if possible as this will aid in recoil control. If you cannot do this then consider a longer, not larger, handle. Obvioulsly a gun with minimal recoil is less of an issue and this accounts for the noticably longer handle on the 1860 Army (.44) as opposed to Navy (.36).
The hold on the handle is more from the side than the rear and much of the backstrap should be visible to the shooter at all times. This puts the shooters finger rather more forward and allows the trigger finger to go well through the trigger guard without pressing against the side of the frame in any way. The knuckle on the second finger should be past, not behind, the trigger guard. This saves bruising during recoil.
For me, the trigger is squeezed with the pad of the second joint on the Remington but rather closer to the second crease on the Navy.
When cocking the hammer, the index finger should remain in the trigger guard and push forward firmly. With the other three fingers pushing back firmly, the result is a very strong hold on the gun even with the thumb completely free. I have read advice to the effect that the trigger finger should be removed while cocking... A bad idea I feel because the hold on the gun becomes very flimsy as only three curled fingers are doing the job. In any case with the method described it is not possible to remove your finger from the guard. Note that this hold on the gun also brings the thumb much closer to the hammer spur.
The thumb should be hooked over the hammer spur using the entire first joint. Immediately the excellent design of the high hammer spurs on single actions becomes apparent. The thumb is then pulled back to the side full cocking the hammer and then the thumb continues down onto the handle in one fluid movement.
This will take some practice to achieve but the possibilites that become available are; a very firm and powerful hammer control, a greater ability to overcome the strong hammer spring strength of the Cap and Ball revolvers, a quicker action and a much firmer hold on the gun.
I have included some photos to better demonstrate my technique. Note that the guns are Remington New Army and Navy Colt but the technique works on other guns. The main consideration is that many newer designs have a lower hammer spur that comes back further, so again you mileage may vary.
Good luck and happy shooting.