As winter progresses, fish under the ice are going through changes. If you keep up with their movements, you can still be successful. If you don't, you will likely get skunked.
Ice fishing is a challenging sport. There are so many variables that it's hard to keep up, sometimes. You have to learn to notice the most subtle changes and capitalize on them immediately. The pattern that you relied on the day before can be completely ineffective the very next day. Focus on following the fish as they migrate, and keep track of these movements for future outings. Locating where the fish are is the first part of the battle, while figuring out what they want to eat and what presentation they want is equally important.
As the season progresses, oxygen levels in the water begin to drop. This forces the fish into deeper areas of the lake, which tends to make them harder to catch. As mentioned before, locating the fish is the first part of the battle. There are several methods used to find them, but they all have one thing in common. The bait you choose can be more important at this time because the fish are becoming more lethargic. The way you rig, jig, and the size of bait used can make a big difference in your success level.