Three things worth mentioning that have nothing to do with brand, material, etc of the glove/mitten:

1) Glove size - Insulation is provided by trapped air, not the material itself, so it benefits a rider to get gloves a size larger than his/her summer gloves even if they feel a bit loose. This allows the insulation to keep its loft while trapping additional air between the skin and glove. If you are layering gloves, you need to make sure that each layer is progressively larger for the same reason. If your outer glove fits well by itself, it is probably to tight to put much of a liner in. Snug gloves work against you in another way, the mild compression further reduces blood flow to the fingers, which has already been compromised by the colder conditions. If you are wearing mittens, you should easily be able to wiggle your fingers inside the mitt, even when wearing a glove type liner.

2) Hydration - You don't feel as thirsty in cold weather and in many climates the air is drier than in the summer. You may not sweat much but you are still losing a huge amount of fluids. One of the first ways your body compensates for fluid loss is vasoconstriction. In order to keep your blood pressure normal when your blood volume is down, the vessels become smaller in diameter starting at the fingers and toes. Your fingers and toes don't have muscle to generate heat, so the heat must be carried there by the blood vessels. If the vasculature in your hands is constricted there is decreased incoming heat from the muscles of the arms and core, so no amount of insulation will keep your fingers warm.

3) Protect the Core - There is an old saying "If your toes are cold (or in this case fingers) put on a hat". This tip goes hand in hand with #2 . Your fingers need a copious blood supply to stay warm. Faced with survival in cold weather, one can survive sacrificing a few fingers or toes to frostbite, but hypothermia of the core can kill you. Your body has adapted to protect the core and sacrifice the extremities, so if you allow the core temperature of your head and torso to drop (this isn't the same as having a mild surface chill that might make you shiver a bit), your body will protect the core by shutting down the circulation to the hands and feet. Conversely, if the core is adequately warm and you are working hard enough to generate excess heat, the circulation to the feet and hands is increased to act as a radiator. There is a bit of a trick to keeping the core properly warm in below freezing weather. You want to stay warm enough to be comfortable but cool enough not to generate a lot of sweat. Appropriate layers and 3/4 or full zippers to adjust are your friends here. I find that cool but not shivering hard at the start and comfortable but not sweating heavily during the working part of the ride, works out about right for me and I've ridden frequently in sub-freezing weather and occasionally in sub-zero F weather.