Hi,
Those methods are reliable ones but it is not so much what you fish but where you fish. Carp tend to shoal tightly when it gets cold but during mild spells they tend to be more active. I find it is better to walk around the pool with nothing more than a rod with an Arseley bomb on it and cast around to see where the fish are. You will get liners as soon as you find the shoal. Alternatively, look for likely areas where the fish may be, like the North East corner of the pool where South westerly winds have been blowing. Carp tend to move towards the center of the lake when it is very cold and are often shoaled up anywhere from mid-water or just off bottom. Even if you fish in the right area, carp will not always feed until later. If the water is sheltered from strong winds then the waggler is the best method for catching carp, especially when it is flat calm. A few pints of maggots and a small tin of sweetcorn should be enough bait to last the session. The good thing about the waggler is that it allows you to fish off the bottom if you are getting too many liners. Carp can be caught at half depth in cold weather.
I hope this helps