This time I went armed with a plan: the advice I'd been given was to bait heavily and fish a rod tight to the reeds and a 2nd a rod length off the reeds on the far margin with a 3rd rod fishing as 'chuck it and see'. I was also going 'large', using 20mm custom boilies from Innate Baits and size 6 hooks (which still seem massive to me!).
And the plan paid off!
Massive thanks to Innate Baits, the custom 'signature' boilies really did the business.