The censer (sometimes called the thurible) is usually found on the altar. Incense is burnt in the censer in order to symbolize the element of air.
It doesn't have to be fancy, a plain one will work just fine. It's what it symbolizes that is important. Censers can be made from all sorts of diverse materials although a form of metal is the most common.
Some censers will be designed to be hung, or swung. And these are fine if they suit the way you work. For convenience sake a freestanding one is usually a much better option. At the end of the day, a plain wooden incense holder is fine, although it is obviously nice to have something a little fancier.
There are many different kinds of incense out there, with all different kinds of scents. All are suitable for use within your censer although you may benefit from the association of a particular scent when doing spellwork. Some scents may be used to represent particular virtues, or to honor a deity. It doesn't mean though, that you can't use a particular scent you like just because there is no strong association with what you are doing. Use whatever works for you.
