The black or blue satin silk bow tie is the most commonly used for the reason that most tuxedo lapels are in satin, and for tradition the fabric of the bow tie and the tuxedo lapels should match, so satin is the favored material for the making of the bow ties.
The quality of satin can be of different materials like cotton, wool and silk, even if on the market there are many cheap models in polyester or in a blend.
With no doubt the best choice is always silk, better if high quality Italian woven silk, that comes in different weight and weft like grosgrain, moire, shantung and faille. Bow ties can be in one-size-fits-it-all or in different neck sizes for a better fit.
The classic shapes of a bow tie are the butterfly, the batwing, the pointed ends and the single end.
The butterfly bow tie is a great classic piece, to wear for a timeless elegance. The batwing bow tie is cutted in a rectangular shape, easy to produce, cheap and now out of fashion. Harder to find is the pointed ends bow tie, which is chosen by the gentleman who wants to wear something different from the usual bow ties he already has in his wardrobe.
And then there is the single end ones, the king of bow ties, slim and lively, with a simply shape for a nonchalant look, the one preferred by the dandies of the Twenties in order to look the more dapper as possible. Also the single end is not easy to find on the market.
The important thing is always to choose the size of the bow based on the build and head size, to best fit the correlation. A jumbo butterfly bow tie is surely appropriate for a strong body shape, but not for a tiny face, in order to avoid the Easter egg effect.
In general, the bow tie has not to be larger than the face or the neck. Regarding the social occasions where to wear the bow tie instead of the tie, these are different and also during the day the gentleman can dare to wear a bow tie for a dandy look on a cardigan or a velvet blazer, provided that to match gaudy colors or patterned bow ties.
There is just one rule to always respect: with tails you can only wear a white bow tie.
For the rest, go ahead with the most oddly assorted outfits, for a fine and dandy look also by day, at the office, even with a pair of suspenders and a pocket-square.