1. Playing was hands-together early on in practice (and I might add - go back and forth between separate and together)
2. Practice was thoughtful, as evidenced by pausing to look at the music, singing/humming, making notes on the score, etc.
3. Errors were addressed right away; the precise location and source of each error was identified accurately and rehearsed toward correction.
4. Target passages were repeated until the error was corrected and the passage was stabilized.
And one to rule them all.....one strategy overall was most impactful: STRATEGICALLY SLOWING THINGS DOWN !
OK, now I've got to get back to work on that Debussy.............