If you are going to attempt to improve manual flying skills, you start at the very beginning during the SE phase at the ATOs. The critical ability is accurate trimming. Without this basic skill, you are wasting your time. The six round dials are needed to ensure that the basic scan technique is learnt.
You build on these skills when the student moves onto twin engine phase. You need to ask what style of instruments are best to build on what has been achieved. Again the ability to TRIM accurately is a vital ingredient. Reduces the workload and increases the situational awareness (the ‘seesaw’ analogy ~thanks Chris Brown).
From there, the MCC phase needs manual flying preferably at the very start of the course, and a RAW DATA ILS from base leg at minimum clean speed during every alternate exercise. Power / Pitch couple: the new aspect to practice.
The type rating course then needs to consolidate these skills. A review of the OPC/LPC is probably needed.
On the nice days line flying, pilots must be encouraged to keep these skills ‘on the boil’. Keep the practice going and the skills will be retained. The less you do, the less you want to do. A basic lack of confidence will develop. A gentle spiralling down process will take place and you will end up where we are now.
Bottom line: good training and continuous practice.