Millers were paid on a commission basis. You brought so many pecks or bushels (1 bushel = 4 pecks = 8 gallons dry volume) and the miller returned you the flour in sacks less his cut (and the manor's cut too). Millers were generally suspected of taking more than their agreed share. A good source for this is a song (the version I know is from the USA) called "The Millers Will" or "The Miller's Sons" where each son had to tell the miller what share they would take if they inherited the mill. Ralph (who would take half) lost out to Paul ... . Chaucer also alludes to this in "The Student's Tale".
Weavers were paid "by the piece" (sometimes nowadays known as peice work or piece rates). Every week, the cloth merchant brought ready-spun yarn and collected the finished cloth. The weaver was paid for each "piece" on the basis of size and quality. Again, there was the opportunity to steal the finished product, which was worth far more than the weaver was paid. During the mediaeval period, this was considered a heinous crime as the whole economy of England (and possibly Wales) depended on exports of wool cloth to Europe.
When "mills" (factories) came into being at the Industrial Revolution, large numbers of automated looms were set up powered by water (and later steam). Less skill was needed for these and people were paid less. The hand loom weavers were regarded as having been cruelly treated and there was a great deal of sympathy with them.
Tailors were paid differently again. They were skilled workers who needed to first measure the customer then agree on terms for each piece of work. The cloth was provided by the customer, who also paid for it to be made up. Any spare cloth was kept by the tailor as a "perk". There were 3 ways a tailor could steal from a customer. Firstly, the amount of cloth required could be grossly overestimated. Then, the tailor could cut the cloth in such a way that large pieces were left but the finished product was "badly cut". Finally, the tailor could "skimp" the clothes, using less cloth than was really required and, again, producing a poor quality product. On top of all this, the customer displayed the tailor's workmanship to the public, so if he had been cheated it was often apparent to everyone (as in the tale of The Emperor's New Clothes).
This any help?