Pastiche
Pastiche describes a literary or other artistic genre. The word has two competing meanings, both discussed below.
In much current usage, the term denotes a literary technique employing a generally light-hearted tongue-in-cheek imitation of another's style; although jocular, it is usually respectful. Examples in the English language include the many stories featuring Sherlock Holmes written by writers other than Arthur Conan Doyle and David Lodge's novel The British Museum Is Falling Down (1965). Much fan fiction relies heavily on pastiche for any effects it might have.
Pastiche is also used in non-literary works, including art and music. For instance, Charles Rosen has characterized Mozart's various works in imitation of Baroque style as pastiche.
Pastiche is also used less scrupulously to take commercial advantage of popular styles or subjects. Many genre writings, particularly in fantasy, are essentially pastiches.
Pastiche can also be a cinematic device wherein the "author" of the film pays homage to another filmmaker's style and use of cinematography, including camera angles, lighting, and mise-en-scene. A film's writers may also offer a pastiche based on the works of other writers (this is especially evident in historical films and documentaries but can be found in non-fiction drama, comedy and horror films as well).
See also parody, fan fiction, doujinshi
When it was new in English (late 19th century), pastiche was used with a rather different meaning: a work was designated as pastiche if it was cobbled together in imitation of several original works. As the Oxford English Dictionary put it, a pastiche was "a medley of various ingredients; a hotchpotch, farrago, jumble." This earlier meaning accords with etymology: pastiche is the French version of Italian pasticcio, which designated a kind of pie made of many different ingredients.
Over the course of the 20th century, pastiche came to shift in its meaning, so that now it can be used by educated speakers as described in the first section above, without any necessary connotation of hodge-podge. However, some readers intuit the "hodge-podge" reading to be the dominant or even the only meaning. The variation almost certainly results from the fact that the word is fairly rare--most readers acquire their sense of the word from just a few examples. In light of the ongoing semantic drift, it would seem that writers should use the word with caution.
Pastiche as imitation
Pastiche as hodge-podge