ToxDrawace has posted a useful guide on Reddit that lists all of the provisioning ingredients for all writs (levels and factions). There are several uses of this list including,
Zenimax Online Studios has posted a nice summary on Master Writs on their website.
Master Writs are mysterious, exclusive contracts for high-quality and very specific equipment, or very specific alchemical substances, enchantments, or provisions.
http://www.elderscrollsonline.com/en-us/news/post/2017/02/15/homestead-guide-master-writs
Only the finest master crafters in Tamriel receive special master writ invitations from Rolis Hlaalu, the Mastercraft Mediator.
To become a recipient of these prestigious documents, crafters have to be certified, be recognized as a master in their profession (Level 50), mastered all of the proficiencies in those professions (Solvent Proficiency 8, Metalworking 10, Tailoring 10, Potency Improvement 10, Recipe Improvement 6, and/or Woodworking 10).
Once you successfully complete a master crafting writ, you will be rewarded with writ vouchers that can be used to purchase special recipes such as the target skeleton, legendary furniture for each profession, components of the Aetherial Ambroisa recipe, and more.
Tips: See Making of a Master Crafter
There are those who are content to contribute to society by making stuff for their income or to supplement their income on the side.
Writs are daily quests for crafters. To obtain writs from the Writ Boards, you first need to be certified by master crafters.
Once certified, a crafter can obtain one daily quest for any, or all, of the six crafting professions each day.
Continue reading ESOTU Writs: Do you know about the Crafting Dailies?
The Vaniverse Gaming has posted an interesting video on the mechanics of Furniture Crafting to be included in the next ESO updated called Homestead. He visits each of the different types of crafting stations and introduces the new “recipes” and crafting currency. Duration: < 18 minutes.