In winter, I love to start the day with a cup of tea to warm up my body and mind. Here, I'm brewing my organic Concubine Oolong from Dong Ding. Roasted and high oxidized Oolongs (or even fully oxidized reds) are the teas that are most likely to give you warm feelings.
The pink/salmon designer Chabu with white plum flowers in the middle also provides a warm background for my Chaxi. The white porcelain has an 'ivory' color that adds a little bit warm yellow color to the brew.
In winter, I also prefer to use an Yixing teapot to brew tea most of the time. It's not just for the beauty of such teapots, but for the better heat retention of their clay. The leaves don't cool down as quickly in the teapot and this helps to extract (a little bit) more out of the leaves.
Cha qi, the tea's warm energy is what makes good tea different from other hot beverages. It's like the difference between a plain electric heater and a ceramic oven fired with wood. The electric heater gives heat when 'on' and quickly cools down when 'off'. That's how most hot beverages work: their warming effect is very short lived. With tea that has a warming chaqi, on the other hand, the warmth stays and dissipates only very slowly, like a wood fire in an oven. It's this slowly calming fire that warms me up in winter!