Unfortunately, most of the species around here are what would probably be called warm water species; largemouth & smallmouth bass, sunfish, snakehead and catfish . So while the seabass are off spawning, things can seem a bit slow. Luckily there are carp everywhere and although they're not as active as in the warmer months, they're certainly still feeding and very catchable. I often talk to people who fly fish for carp but stop when it gets "too cold" for them. I think unless the water is frozen over then it's warm enough to catch carp on the fly. Admittedly this is more true of rivers than lakes, but that's just down to finding the fish in water where you can spot them. While still water fish will often seek out deeper water often away from the shore, in rivers you've a good chance of finding a fish that will eat a fly. In fact, I think they are at their easiest to capture at this time of year!
One of the best things about winter carping is that you don't need to get up early. With the short days and low winter sun, there's little point in rushing to the river at the crack of dawn. Far better to relax, enjoy your coffee and let the sun get a bit higher and, hopefully, bring the temperature up a bit. Around here, 10am seems about right most of the time and gives you roughly 4 or 5 hours of fishing before the low angle of the sun makes the glare and shadow too extreme for spotting fish and keeping track of the fly at anything more than dapping range. Finding fish is pretty easy, it's always worth checking any of the features that warm up quicker or are generally at a higher temperature than the surrounding areas are a good start; shallows with dark bottoms and slow flows, walls on the north bank, springs and warm water inlets. That's not to say you'll not find fish tailing in riffles. You will and they'll be worth a cast but I think it's better to play the percentages than waste good light looking in the cold shallows.
When you find fish, you'll find that they're much easier to approach than in the warmer seasons. You still need to approach carefully and be reasonably stealthy, but you have a bit more leeway. Presentations can be much the same as summer but they'll not move far for the fly or pounce on it so make sure it finds bottom right in front of them, and be prepared to wait for the fish to eat properly. It's a good idea to use a fly you can see so stick a bit of fluorescent material in there, or even use a glo bug- 20mm of magenta and chartreuse unweighted or with a bead is a good choice. The bright fly isn't just for you though, carp actually lose visual acuity when they're cold. It's something that bait anglers have known for years, making fluorescent pop-up boilies and artificial corn popular winter baits. I basically follow their lead and I like the results, not least because I can no longer get away with easy to spot flies like that on my local in the summer months. I've terrorised them out of that!
I was out on Monday and caught a few even though there was still ice on the bank at 1pm., I've a few more weeks of carp before the seabass return from the spawn and occupy me till things get a bit warmer and the other species start waking up.