Hi woz, Ive been fishing Arnfield regularly this year and it's a fabulous place. If I were you I would go for a boat, they are extremely easy to handle and Steve or Alan will show you the ropes.
I spoke to Steve the other day and he's of the opinion the fish are down slightly. In this case a method I find extremely successful is a two lure setup on an intermediate or D5.
The water at Arnfield is quite heavily peat stained. With this in mind I found the ideal set up when the fish are down is to use a white lure on the dropper and a darker lure on the point. I had over 20 fish on my last visit with this setup. The flies I was using were a hot-head apptitiser on the dropper and a glod-head damsel on the point, fished about 10/12 foot down with a slow figure eight. You'll find the blue's hitting the white fly and the rainbows hitting the damsel.
If the fish are on the surface, a pair of Klinkhammers will do some damage.
You can read a bit more about my trips there
here.
Hope you have a good evening woz. Be sure to let Steve know I'll see him tomorrow. Thanks.