Which item is typically used for preparing and consuming cocaine?

The use of small mirrors in the context of preparing and consuming cocaine is associated with the practice of lining up the drug for snorting. A small mirror can provide a flat surface that allows for easy division and arrangement of the cocaine into lines. This method is common among users who prefer to inhale the substance for its quicker onset of effects.

The other items listed have different uses; for example, plastic bags are often used for packaging and storing drugs rather than for preparation or consumption. Cigarettes can be a means of consuming substances, but they are not used for cocaine specifically. Glass vials may be used to store various substances but do not fit the common method of consumption for cocaine. Thus, small mirrors directly relate to the method of consumption, making them the correct choice.