I've just won a match at Leicestershire commercial fishery complex Mallory Park with 70 carp for 186lb. And a trick I employ when fishing a hemp and meat feeder, using Sonu Super Scent hempseed, helped me to my victory.

Everybody knows that when hemp is cooked it leaks off oil, which  floats.
And when you are fishing the feeder, you don't want all the carp swimming up well above the feeder, gill feeding on that oil.
You want them down on the deck, looking for your hemp and bits of luncheon meat, especially the one with the hook in it.
So what I do is use my hair-rigging landing net, which is made from ultra-fine mesh, and I open a tin of Sonu Super Scent hemp, tip it into the net, and give this a swish around in the margin.
All the oil comes off the hemp and leaves you with grains that aren't leaking masses of floating oils.
I then transfer the hemp to a bait tub and just cover with water, to prevent it drying out.
I used two tuins of Sonu hemp in the five hour match, and two tins of luncheon meat. In like to use a cage feeder in shallow water and I reckon a ratio of two-thirds meat to a third of hemp is about right for the feeder.
At Mallory, where I had drawn on Pool One, I teamed up an 11ft Preston Innovations Carbonactive C Series rod with a reel carrying 8lb Korum reel line. The feeder was free-running and was stopped by a Korum quick change bead, with a 20-inch hooklength of 0.20mm mono, finished off with a size 16 PR36 hook, with a Korum Quickstop tied on to the hair.
With regards to hair length, I like the meat to hang nicely, just off the bend of the hook, so that it behaves naturally when carp are in the vicinity.
Accuracy is the key when fishing tight to a far bank, as I did in this match. It was a cast of about 40 reel turns and the bites were the 'off the rest' variety once the fish found the feeder.