Glass provides a nice view of the tea inside. It’s also essential to the presentation of wrapped or folded tea such as tea flowers.
Some tea pots are designed so they can be used to boil water on a heating element (such as a stove), and can also be kept warn on a heating element. Glass and some ceramics will break if put on a heating element. A common characteristic that I’ve noticed is a metal collar that makes the tea pot look like a coffee pot, though the shape is different.
A “Brown Betty” tea pot is quite commonly used in many households, though with tea culture from various sources spreading, other pots are often seen too. One appealing aspect of the common colour used for the tea pot is that it doesn’t show tea staining very well.
Some designer teapots can be hand painted, have unusual shapes (such as squares and triangles), and unusual colours.
Paderno makes some nice shiny metal double walled metal tea pots which may help to retain heat.
When looking for a tea pot, consider how it will be cleaned. Built in strainers are nice, but may be difficult to clean. Also, you may want to consider the size of the top opening verses the size of your hand so that you can easily reach inside for washing the pot.
A coffee press (or even coffee pot) can double as a tea pot. I don’t recommend using it for both as coffee coating can cause a scummy residue to form around the edges of the container and float in the tea.
A small individual serving tea pot can be a nice option, especially when re-using tea leaves as is customary with some tea cultures. In such cultures, I’m told that attention is payed to not “scalding” the tea by using water that’s too hot and using a first pot quickly drained called “washing water” which is sometimes drained into the cup to wash it out. “Washing water” also serves to “steep the pot” providing removal of some residues and warming the pot to better retain the heat of future cups. I suspect some tea leaves may need to be rinsed off too. Using this method, I recommend varying the brew/steep time according to the number of uses the leaves have seen.
Yerba Mate is sometimes consumed using a gourd and a metal filter straw. If using a gourd, it’s difficult to see the leaves. The Columbian that introduced me to using a gourd said that it’s common to re-use the leaves in the gourd. I’ve seen restaurants like La Fiesta using a coffee press to give a nice visual display of Yerba Mate. Of course with leaving leaves in, I recommend consuming the tea within the first few minutes to prevent too much caffeine from leaching out.
A good China/porcelain tea pot can provide an appealing design with matching cups, saucers, creamer, sugar bowl, serving tray etc.. The rims are sometimes decorated with a thin line of gold. While very visually appealing on their own, they can be impractical to wash due to how delicate they are, and likely should be washed before tea stains set in. I have not seen any tea stains set in China or porcelain, but at the cost it doesn’t seem worth the risk. I have seen tea stains in ceramic tea cups, even those with a glossy finish.
In one episode of Sherlock called The Blind Banker tea pots from China in a museum must be washed with tea regularly to keep from cracking, and to help them slowly get a nice tea colour. I have not heard of this outside of this tv episode and expect that such a pot would be very impractical even for an avid tea drinker.