There is a lot of contemporary documentation on pirates, written by their victims and, in the case of the memoirs of A. O. Esquemelin, the pirates themselves, found on Project Gutenburg and the Internet Archive. Including contemporary woodcuts.
My knowledge pertains mainly to the Caribbean pirates on what was called the Spanish Main. As far as pirate dress, many Captains and officers adorned themselves in contemporary “gentlemen’s” clothes, or a hodgepodge of naval uniforms of their period—usually booty from victim ships of various nations, both civilian and military. These ships were English, American, Dutch, Spanish, Portuguese, and French, mostly, as were the fashions and uniforms found in them. Consider that many of these men didn’t change their clothes very often, and the clothes were silks, flannels, cottons and heavy wools. Heavy woolen Great Coats with filigree on the breast and buttonholes were in high demand as they denoted rank and served as protective clothing during raids. Pirates often operated in tropical and subtropical climates. Ships officers, many former navy men, insisted on wearing full dress, including great coats during raids and when around women in pirate-controlled ports like Port Royale, Grand Turk, and Trinidad.
The crew dressed much like the common men and sailors in contemporary cities such as Lisbon, Portsmouth, colonial Boston, or Toulon. Cotton pantaloons, collarless cotton blouses with broad sleeves, broad brimmed hats and scarves/handkerchiefs (as headbands to soak up sweat and around the waist as was the fashion) for protection from the sun, broad leather heavy buckled belts at the waist and across the chest for swords, some were barefoot, some wore the heavily buckled leather shoes of the period, some wore heavy knee-high boots. Again, this was protective clothing. Personal hygiene and daily dental care was nearly non-existent except among certain former privateers, gentlemen, who chose to extend their letters of marque beyond their intended use and become out and out pirates.
Considering the climates they operated in, the effect of weather and sun over period of years, the lack of hygiene, their affinity for strong spirits, poor diet, the infrequent change of clothing, frequent hand to hand combat, the crews stunk to high heaven, were missing teeth, were badly barbered, were quite shabby in their dress, looked much older than their years, and rarely lived beyond 30. But it is said they kept their vessels in immaculate condition, including regular careening and flushing the bilges. Care for weaponry was paramount.
Edward Teach, aka Blackbeard, was said to have jet black, greasy locks below his shoulders and an equally black and greasy long beard which he liked to braid and then light the ends on fire during raids for effect.
Anne Bonney was said to be fond of dresses, but found them impractical in her work, so she and her female companion dressed like common men of the period and often were mistaken for them.
Henry Morgan, owner of vast plantations and former Governor of Jamaica was a gentleman pirate of great success. According to contemporaries, he demanded near-naval discipline aboard his ships, although, like most pirates, he had his men sign the usual standard articles before coming aboard. This was a contract denoting rank and share dependent on skills and experience. Compensation for digits, eyes, and limbs lost during combat were commonly described in these articles. A list of men with appropriate skills for positions such as captain, navigator, first and second mates, was made and from this list the officers were elected. This was common practice among most pirate ships. Ships surgeon was a prized man and there was always a position open for one at near captain’s share. A. O. Esquimelin was a Morgan’s ship’s surgeon and later wrote about it and it is on the net. Morgan saw no reason to change his lifestyle or dress any more than he had to while he was a pirate captain. He was quite flamboyant.
Francoise L’Olonnaise was among the cruelest pirates in history. His punishments were extremely imaginative and sadistic, his murders frequent and arbitrary, his boardings and pillaging were merciless and among the most bloody. He favored black clothing with red shirts and scarves. He and Morgan combined forces on one raid and Morgan was so disgusted he avoid L’Olonnaise’ areas of operation thereafter. Morgan refused to take former L’Olonnaise crew onto his own. But I digress.
These men, for the most part, were badly barbered, dressed in period rags, had bad skin and teeth, were undernourisned, were often drunk and showed signs of frequent beatings and knife fights, and they smelled bad. Some were missing limbs and eyes. I imagine, like most drunks, these guys were pretty ornery. Not the kind of guy you’d want to take home to mother.
I think you would find Project Gutenburg and Internet Archive helpful.