Witches consider themselves as a separate entity from other practitioners of the black art, and witchcraft as an art form distinct from sorcery and magic. You should never refer to a witch or a black sister as a woman or crone, as the female gender is regarded as only one of the prime requisites which are required to become a witch. To mention 'woman' or 'crone' when meaning 'witch' would be pointed out to you immediately as a major error (and if you said that to the face of a witch then it is likely you won't wake up the same shape and colour as you went to bed).
All witches have a strong sense of identity irrespective of their social standing; they are all witches. This separate identity extends to a national dress - virtually anything black, as long as it's not trousers or short(s), preferably antique (red and white hooped stockings are optional); a national emblem - the broomstick; a national (also mandatory) piece of headgear - the hat, preferably skewered in place with batwing hatpins. These, together with separate educational (a witch knows what's real, what's not and knows the difference), legal (a witch is always right), financial (a witch doesn't pay for anything) and religious institutions (a witch only believes in herself, but that is no reason to deny anyone some peaceful rest) all extend the national identity.
Witches also have a strong sense of history. Witness two examples of witches from the past: Aliss Demurrage - Black Aliss - a very powerful witch, so called because of her fingernails and her teeth, not her exploits, which were the result of bad temper rather than actual malice. Some of her best-known involved turning a pumpkin into a royal coach and sending a whole palace to sleep for a hundred years; Goodie Whemper - maysherestinpeace - a research witch who died in an accident while testing whether a broomstick could survive having its bristles pulled one by one in mid-air. The answer, apparently, was 'no'.
Unlike wizards, who like nothing better than a complicated hierarchy, witches don't go in much for the structured approach to career progression - you start a witch and stay a witch, perhaps gaining a few warts and losing a few teeth for street credibility as you grow older. It's up to each individual witch to take on a girl to hand her cottage over to when she dies. Witches are not by nature gregarious, at least with other witches, and they certainly don't have leaders.
Sabbath management is quite common. Coven meetings are scheduled in advance with proper agendas, as well as tea and scones, and are a part of being a witch, not an interruption from it. Coven meetings usually begin and end with social conversation and can be quite informal. Coven members do not leave the meeting before it is finished, or engage in communication between ordinary mortals during the engagement. Formal communication with a witch should not begin with a personal visit, unless you are either brave, stupid or both. The usual method is to send someone else (who is preferably naive, in addition to brave or stupid) explaining the reason for your proposed visit, and requesting an appointment. After a few days this can be followed up by either sending another person (assuming the first never made it back) or going yourself.
Witches are not as formal as is believed on Discworld, but it is a culture where a direct display of feelings is suppressed. Mature witches refer to themselves as Biddy, Gammer, Granny, Mother, Mrs, Nanny or Old using either their last name, or their first and last name. Generally, witches who command respect can choose to have the populace call them whatever they wish. Among themselves, however, first names are always used.
Bowing is for first meetings. Witches who meet regularly do not bow. The normal formal greeting is 'Wotcher!'. It is not a question but a statement and expects the reply 'Wotcher!' in return. There may be an impression of coolness and formality, but it is not unfriendly, only a form of politeness and reserve. Communication can be imprecise and vague, which can be misleading to outsiders used to instant plain speaking. Nothing may appear terribly serious. Humour is accepted at all levels - public or private - and witch humour is dry, witty and self-deprecating. In essence, sardonic.
Witches classify each other by speech, manners and dress. Senior witches wear many layers of dark petticoats, culminating in a long dress, the red and white hooped stockings and hobnailed boots being an important signal. It is meant to be recognised, so you do not refer to it. You should not wear either of these items of apparel - nor the (in)famous willow reinforced, battered pointy black hat - if you are not entitled to wear it.
Punctuality is respected but it is acceptable to arrive within a few minutes of the stated time. Socially it is normal not to be on time, but woe betide you if you keep a witch waiting for too long. An invitation from a witch will say 7.30pm for 8.00pm, which means you arrive about 7.50pm. The twelve-hour clock is still used, with am and pm. Witches will also still talk of inches, yards and miles instead of centimetres and metres, and gallons instead of litres. In cooking and brewing also, pinches, handfuls, and skooshes are far more meaningful measures to a witch.
Witchery is about herbs and cursing and flying around at nights and generally keeping on the right side of tradition, not dancing skyclad around cauldrons all day or night (young witches take note). It's also about headology: you can't help people with magic (see the mess wizards make) but you can help them by doing real things. Essentially, headology (that wondrous, mysterious and womanly logic) is about glaring and tricking; making people believe you're a witch is all part of that battle.
Back to Amber's Coven.