This is not a subject I have studied. However, I have read up on pagan religions in Britain, and I have just spent some time doing Google Image searches for "mediaeval pictures of witches" and similar search terms.
The overwhelming majority of images from the time show normally dressed people, usually women, wearing ordinary hats/hoods of the time.
Even some of the later pictures tend to show witches with their hair uncovered and blowing in the wind, or wearing ordinary hats. Nudity is a common feature.
The only picture I found of a "witch" in a pointy hat was one who had been convicted and was being led, bound, and wearing what looked like a dunce's cap: a tall pointy "cap of shame" with no broad brim.
Preliminary conclusion: the pointy hat was a later invention.
Most of the pictures do not show the "witches" wearing black. However, as many were older women, it is possible that many were widows and dressed accordingly.
As others have pointed out upthread, the broomstick and the cauldron or kettle were common items in any person's house.
A cauldron could maliciously be interpreted as being used for brewing potions and poisons.
As for the broomstick: flying is a fairly standard example of "extraordinary" or "magical". Whether we look at Greek or Norse mythology, bible stories, or even some modern fictional heroes, someone with a special power often has some tool, prop, or piece of attire they rely on for that power.
As for all the stuff about hallucinogenic ointments being "applied internally" with the handle of the broomstick, I think that says a lot more about the men coming up with the stories than it does about the women accused of it.
The broomstick being phallic and the cauldron being "feminine" is just overlaying Freudian orthodoxy on an earlier set of beliefs. If it's longer than it's broad, it's phallic; but sometimes a cigar is just a cigar.
Many years ago, I studiously waded through
The Pagan Religions of the Ancient British Isles (Ronald Hutton) mainly looking for evidence for or against the supposedly pagan origins of Morris dancing. (No evidence whatsoever.)
The overwhelming impression I got from this book, and other reading I have done, is that there was no "pagan religion" in the sense of a single unified set of beliefs comparable to the Christian church. A witch from Devon would have no knowledge of a witch from Kent or Newcastle. Why would they wear the same things, or use the same accoutrements?
Folk beliefs and customs persisted in different areas, and there were similarities, but there was no consistent unified whole: no official dogma, or clerical class. If witches existed at all, they were not part of some national or European movement. They were individuals and small groups operating discreetly on the margins of society.
In a time when witchcraft was punishable by a painful and humiliating death, why would any witch wear a costume to advertise her trade? The buying and selling of potions, curses, and incantations would have been a secretive affair, with risk on both sides.
I think that the modern image of the witch with a pointy broad-brimmed hat, broomstick, cauldron, and cat, is simply a recent convention: a shorthand to make witches easily identifiable. For comparison:
- The popular image of Santa Claus in red trimmed with white fur is a fairly modern invention.
- The popular image of the pirate with a selection from wooden leg, hook, eye patch, and parrot, is a modern invention.
- Most cowboys did not wear the familiar Stetson style hat beloved of westerns.
- Sherlock Holmes did not wear a deerstalker or smoke a curved pipe in the original stories.
- Most desert islands are more than a few yards across, and have more than one tree — and it is not always a coconut tree.
- Most African tribesmen did not wear grass skirts or have bones through their noses.
There were no doubt some people who believed that they were witches, and some who were simply scammers of their time, but the vast majority of "witches" in mediaeval Europe were just poor bastards who suffered at the hands of the hysteria, superstition, and politics of the time.
Pratchett's witches are endearing and engaging characters, as is the witch in "Room on the Broom", and they wear their ritual costumes proudly. It's pretty weird, when you think about it, that we have somehow converted the victims of up to 100,000 executions of the unfortunate, the bullied and the deluded into a romantic or humorous archetype.
