After watching too many videos:
Regular washing--a good spray of water, then dry with micro-fibre towel.
Dusting--horsehair brush gets the dust and 'bits' off and doesn't rough up the cloth; or lint roller.
Soap wash--(rarely) '303' fabric top cleaner.
Protect--(haven't used it yet, maybe once a year) '303' fabric protector.
The car is kept under cover and only rarely parked in the open. The top continues to look brand new after 4 months, 5000 Km.