Yep, start of with the smallest punch you can get away with, if the fish are "having it" ,up a size of punch. You can wrap the bread in foil to keep fresh,cut a slice into 4 so you have 4 individual small slices, so if one does dry out slighty you are not wasting a full slice. As I have mentioned I never prep it, just use straight from the bag, it is softer that way, If using liquidized bread as feed, prepare about 10 days beforehand, Liquidize, riddle, freeze. Keep doing this to same batch it will become very fine and will act as an attractor and not feed the fish off, Feed a small nugget and fish for bites, only re feed when bites dry up. Use Warbys toastie . and fish as fine as possible, as you know cold weather can mean clearer water,it does round here, you can see part way across one of the canals in winter. You can feed a few grains of hemp with liquidized bread ,that gives you the option of fishing hemp later on in the session. And have 2 swims going so you are not plundering one swim all the time. Good Luck. Others may give you different advice, the above is the way I do it on the canals around here. @mikench a sonubaits F1 goo works in the summer on bread, it gives off a haze as it dissolves in the water,People have mentioned most things already, but the thread reminded me of my fishing mate's unorthodox "punch" fishing. I don't fish punch often, and I find the method a bit fiddly - prep'ing the bread, keeping it from drying out, punching bits on a hard surface, knocking odd bits off shipping out etc - so I walked down to see how he was doing with it. He was taking his bait out of a lidded box, which was tiny squares or triangles of rolled bread cut on a breadboard at home. He was catching roach every put in. Typical triumph of skill over equipment - I'd watched him bag up on the stick for years before I noticed he'd snapped a couple of inches off his rod tip, and the second ring was now the tip ring.
I've just bought the cheap winter card for a club that has some good canal roach fishing at Loughborough, and I gather you need to fish bread in the clear water, so I'll have to brush up on it, if anyone has any good tips.