It occurred to me while coaxing hits out of a somewhat unusual trigger pull on my heirloom Diana 25 what 'consistent pressure' during a trigger pull means.
I think of it as sweeping the finger back consistently, with no acceleration or deceleration through the movement. Since there will be a trigger to resist such movement, the key is to maintain the same level of force as though there isn't an obstruction. Any acceleration or deceleration that is transmitted to the gun will probably move it. (Perhaps I like this because it's a Grand Unified Theory of Trigger Pulls, and covers both DA and SA, but I digress.)
This would explain the trigger snatch (rapidly accelerating to 'catch' the sights on target, resulting in a jerk). I also noticed while dry-firing that in a trigger with a bit of overtravel, too slow a pull will cause an acceleration when the trigger jumps back as the sear lets off, resulting in sub-optimal results; perhaps counter-intuitively, 3-second breaks were smoother than 10-second breaks.