In terms of basic cut, we can learn a lot from upper class/upper-middle class English and Low Countries portraiture of the time.
At the first settling of Jamestown, in 1607, men's clothing did not look very different from the way it did at the end of the reign of Elizabeth I. The basic pieces of dress were the doublet, trunk hose, and canions. The doublet was essentially a jacket, cut with long sleeves, a low waist, and very short basques (skirt-tabs) along the bottom. Trunk hose and canions were both worn on the thighs: trunk hose were the stereotypical paned "puffy shorts" we often see in Elizabethan productions like Shakespeare in Love, and canions the close-fitting breeches worn beneath them that stretched down to the knee and met the stockings. Around this time, the trunk hose were falling out of use, and men might wear only breeches that could fit closely or have a moderate fullness. Shoes were typically slipperlike, without heels and with rounded toes, and at the other end of the body, hats had tall, cylindrical crowns and round brims (ie, the stereotypical Pilgrim hat). Black clothing was highly fashionable, particularly among the haute bourgeoisie and the gentry, and the starched, round ruff was still worn.
A few good examples:
"Sir William Paddy", Marcus Gheeraerts the younger, 1600; Oxford College Anon II HM16
"Sir Thomas Kennedy of Culzean", attr. Adrian Vanson, ca. 1600; National Trust for Scotland 45.21
By the time the Plymouth Colony was founded in 1620, fashion had moved on: doublets were cut with higher waists and longer basques; ruffs often sloped down toward the shoulders; trunk hose were less common; breeches were typically fuller; shoes might have a slight heel. Women's clothing - now relevant, since the Pilgrims brought whole families - followed the same lines, with raised waistlines and sloping ruffs. Where women's fashion at the time of the Jamestown expedition featured wide wheel farthingales and tall hair, skirts were supported by nothing but petticoats and hair was worn much closer to the head. In the earlier period, women were more likely than men to have large lace or linen cuffs, but by 1620 cuffs were practically universal.
Some examples:
"George Villiers, 1st Duke of Buckingham", Cornelis Janssens van Ceulen, 1619; LCCMS L.F46.1938.0.0
"Margaret Laton", attr. Marcus Gheeraerts the younger, ca. 1620; VAM E.214-1994
"Sir Thomas Parker of Ratton", Marcus Gheeraerts the younger, ca. 1620; NT 872163
James Hamilton, Earl of Arran, Daniel Mytens the Elder, 1623; TC N03474
Okay, but what did the settlers themselves wear? It's harder to know, because the people on the ground did not generally have the means to have themselves immortalized in paint. It's unlikely that many would have worn a solid, deep black like many of the portrait sitters above: a good black was expensive, and the settlers would probably have had more of a very dark brown or dark grey if they had been going for that. (I'm reading an article right now regarding the shift from scarlet being the most fashionable color in the early 14th century to black and other dark colors by the end of it and later, and I'm wrong here - according to John Munro, black fabric was not significantly more expensive than fabric dyed any other color, except for fabric dyed red with kermes.) A whole range of colors were possible, with pinker/orangey/brownish reds from madder, golds and yellows from weld, and blues from woad being the most common and cheapest colors. Wool was the staple fabric of England at that point as well, and so was the most likely fabric for them to wear. Ruffs were almost certainly off the table, due to the expense of having them washed, restarched, and laboriously ironed with tools made specifically for the task, and the stereotypical Pilgrim falling band/collar does not really start to appear until the later 1620s. It seems most likely that men of the period would have turned their shirt collars down, as in the portrait of Sir Thomas Kennedy of Culzean, and that women would have simply worn gowns that covered them up to the neck. Later waves of settlers in Massachusetts brought luxury with them, as sumptuary laws show, but the first arrivals would not have done so.
