One thing to keep in mind is that once you start practicing cradling, your scores will drop and you’ll likely get frustrated at first. Perfectly normal. Keep practicing and your scores will eventually get better.
Cradling is mandatory on modern Stern’s. Post passes and cradle separations are usually doable from both flippers. Also, because many shots are backhandable, cradling during single ball play can often be beneficial. Doubling the next shot by backhanding the left ramp first on ST is an easy and safe shot. Having 2 balls on one flipper is also huge on a number of Stern’s. Bonus multiplier on AVE and the left saucer on ST come to mind. Both are simple and safe backhand shots with 2 balls on 1 flipper.
I’ve learned virtually everything I know by playing with (watching) better players. If you can’t play with them, watch videos.