Tassel:

A tassel is a ball-shaped bunch of plaited or otherwise entangled threads from which at one end protrudes a cord on which the tassel is hung, and which may have loose, dangling threads at the other end. Tassels are normally decorative elements, and as such one often finds them attached, usually along the bottom hem, to garments, curtains, or other hangings; and to mortarboards.

The word 'tassel' comes from the Latin "tassau" which meant a clasp (as for the neck of a garment), but also later served to denote string ties, which were later terminated in increasingly elaborate tassels. Today, tassels, or liripipes, are found on mortarboards during graduation ceremonies, but possibly also upon the shoes of the men there, really the only other socially acceptable appearance of a tassel among men today. That the tassel is really a universal ornament is seen in versions in virtually every culture around the globe, and even as the 'silk' on a corn stalk, on the breast of a tom turkey, on the tasseled crab, and the "pine cone and tassel" is the state flower of the American state of Maine.

Passementerie
In this craft, a tassel is primarily an ornament, and was, of course, at first the casual termination of a cord to prevent unraveling as its ends which were tied in knots with the remainder of the cord hanging as shreds of it. As time went on, various peoples developed greater or lesser variations of this, until by the time of 16th century France, there was constituted the first Guild of Passementiers who formulated and documented the art of passementerie (pronounced: pahs/mahn/TREE). This art form had the Tassel as its primary expression, but also included Fringes (applied as opposed to integral), Ornamental Cords, Galloons, Pompons, Rosettes, and Gimps as other forms. Tassels, Pompons, and Rosettes are point ornaments; the others are linear ornaments. The parts of a tassel are basically, from top to bottom:

Its Suspending Cord
Its Body, which is usually made up of one or more Moulds
A Skirt of fringe or other ornaments.
The techniques of construction are too elaborate to list here, but there have been a few good books on the subject in French and a few in German. No significant writings on the art from have been in English to date, though a number of minor works have appeared recently about tassels due to the resurgence in interest since around 1980.

Tassels were originally, in the Western World, a series of windings of thread or string around a suspending string until the desired curvature was attained. Decades later, the form was of turned wooden moulds which were either covered in simple wrappings or much more elaborate coverings called "Satinings." This last technique involved an intricate binding of bands of filament silk vertically around the mould by means of an internal 'lacing' in the bore of the mould. These constructions were varied and augmented with extensive ornamentations that were each assigned an idiosyncratic term by their French practitioners. Those practitioners were called in France "Passementiers" (pronounced: pahs/mahn/TIERS), and an apprenticeship of seven years was required to become a master in one of the subdivisions of the guild. The French widely exported their very artistic work, and at such low prices that no other nation developed to mature a "Trimmings" industry as it is called in English. Each era of decor found tassels and their associated forms to be in different stylings suitable to the period, from the small and casual of Renaissance designs, through the medium sizes and more staid designs of the Empire period, and to the Victorian Era with the largest and most elaborate and formal to be seen. Some of these designs are returning today from the European and American artisans who may charge a thousand dollars for one custom-made tassel, to the new innovations of the Chinese who now have established factories that turn out less perfect, but quite serviceable designs duplicating the best of the classic patterns for as little as US$15. Since vitually all militaries have adopted the very plain and service-oriented modern uniforms, there is no longer any call for tassels in that area, and the same goes for transportation and the clothes of people in general, so it is almost entirely period decor that is the sole remaining display of large, fine, tassels.