My preference when floatfishing prawns (stillwater) is to keep a light but constant fall of maggots going in to attract the tiddlers and to fish just off the feed area. Feed too heavily and the carp can move in. You'll probably catch a few anyway if they're in there so it can be a mistake to fish too light - a 5 or 6lb hooklength seems about right.
Cooked or raw prawns both catch fish, but fresh ones have a tougher consistency and stay on the hook far better than frozen.
Despite my best ever perch falling to a prawn it's not a bait I've had great success with.
I've read endless articles, some prefer cooked where others prefer raw, some won't use pre-frozen due to a solution that they are coated with prior to freezing, some use king prawns where others swear by the small ones.
Personally I don't think it matters that much, but then that could be the reason I've never done consistently well with them
I'm of the same opinion as Binks, prawns can be very effective for perch on a given day and be ignored on others. As most fish seem to like prawns, if I'm specifically targeting perch, I prefer to use 'jumbos' and dunk them in predator plus (being careful not to get the stuff on my hands as it's a bu99er to get off).
Personally, if after decent perch, I'd prefer to use lobs or lives/lures..............
Cheers all, Commercial lake no carp so suppose I will float a fat juicy prawn near the Lilly pads and hope for the best and keep throwing small pinch maggots over the top.
In my short time pursuing the stripeys I've found that prawns work on some waters and other waters hardly at all. I fished Stream Valley last year, home of the current record Perch and nearly all the experienced anglers use nothing but prawns over a bed of maggots. My local lake where I've had three 3lb plus perch is a water Ive never caught on prawns, plenty of sturgeon though!