Can you explain your situation a little more?
It depends on the case really.
For sexual assault alone it is rare that a conference in Chambers would be conducted.
Generally speaking it would be a conference before trial on the morning of trial whilst at court.
However, it does depend on the circumstances of the case, the nature of the unused material, whether the solicitors brief counsel in time, whether it is returned to another counsel.
There isn't really a standard procedure.
Can I clarify anything for you?