Crafting

Crafting an item takes a set amount of hours in game dedicated to working on said item, the base amount of hours required to craft an item is determined by dividing the gp cost of the item by 10 (or the exact cost in platinum). Crafting costs GP, not ingredients - however relevant ingredients can possibly reduce the cost of certain items. Crafting homebrew items must be approved by the DM before crafting - to determine cost and hours. The profession(s) that you choose to pursue are considered a feat. The crafting professions that can be learned are Alchemist, Blacksmith, Carpenter, Enchanter, Leatherworker. There are 4 skill levels that affect your overall crafting efficiency.
Novice - Full price - Full hours spent.
Apprentice - 25% reduced price and hours needed.
Journeyman - 50% reduced price and hours needed.
Master - 75% reduced price and hours needed.
To learn a profession you must find a mentor and spend 10 hours and 100 gp to become a "Novice", which gives you profiency with the tools of that craft - from there you must spend increasing amounts of hours and gp with your mentor to progress through the skill levels. Apprentice (100 hours/500 gp), Journeyman (200 hours/1000 gp), Master (400 hours/2000gp).
Hours spent crafting cannot be during a long rest, unless you do not need a full 8 hours or do not need sleep at all. Crafting requires a set of tools appropriate for that item and for your profession. An item being crafted, or your progress towards your next skill level is considered complete when both the hour and gp requirements are met - regardless of which one is completed first.
Magic items costs are as follows (from minor to major):
Uncommon (100 - 500gp) (Cantrip and 1st Lvl Spells)
Rare (1,000 - 5,000gp) (2nd and 3rd Lvl Spells)
Very Rare (10,000 - 50,000gp) (4th - 5th Lvl Spells)
Legendary (100,000gp+) 6th Lvl Spells+)
When crafting scrolls instead of permanently enchanting an item - the above costs become 10% of their original.
Potion costs are as follows:
Common (50gp)
Uncommon (150gp)
Rare (500gp)
Very Rare (1500gp)

Item Improvement
Every piece of armor and each weapon have 3 slots for potential improvement of the item - even after it's creation. These slots are - Quality, Material, and Enchantment.
Quality
The quality of an item is shown through a range from +0 to +3. The ruleset for making an item of higher quality is the same as enchanting an item, +1 being uncommon, +2 rare and +3 very rare. The cost in gp and hours to improve or craft an item of higher quality is added on top of what is needed to create the base item (+0). Once an item becomes at least a +1 it is considered a magical item.
Material
A craftsman may specify what material they are using in the creation of an item, most materials are simply flavor or cosmetic - however some have innate magical qualities and add an additional effect to the item. Using a common non-magical material does not cost any extra gp or hours - but magical materials will have an extra cost associated with using them to craft your item. If the crafter already possesses the material, then it's costs no additional gp or hours. Shields cannot benefit from material effects. A list of all currently known magical materials and effects are listed below. Effects do not stack.
Dragon Hide/Scale (500 gp) This material reduces the gp and time cost of adding a magical resistance enchant to a piece of armor by 25%.
Shadow Hide (500 gp) This dark leather makes the wearer invisible whilst standing still in a shadow cast by a source of light.
Caeli Hide (100 gp) This hide hailing from the elemental plain of air - grants advantage on acrobatics checks when falling.
Ironbark (100 gp) Item's made with this wood are near impossible to destroy non-magically - and the wielder of weapons made with this material have advantage on disarming skill checks.
Motus Wood (100 gp) Originating from the fey wilds - this material (when openly wielded) grants advantage on charisma skill checks when in a forested area.
Mithral (100gp) Mithral is a light, flexible metal. A mithral chain shirt or breastplate can be worn under normal clothes. If the armor normally imposes disadvantage on Dexterity (Stealth) checks or has a Strength requirement, the mithral version of the armor doesn’t.
Adamantine (500 gp) While you’re wearing it as armor, any critical hit against you becomes a normal hit. Melee weapons and ammunition made of or coated with adamantine are unusually effective when used to break objects. Whenever an adamantine weapon or piece of ammunition hits an object, the hit is a critical hit.
Silver (100 gp) Some monsters that have immunity or resistance to nonmagical weapons are susceptible to silver weapons, so cautious adventurers invest extra coin to plate their weapons with silver. You can silver a single weapon or ten pieces of ammunition for the cost.

Enchantment
The item can be imbued with the magics of an enchanter and given a substantial magical effect independent of it's quality and material. See magic item costs above.
Ammunition
Ammunition follows the same guidelines for item improvement - except the cost in gp and hours per unit of ammo is 10% of what is listed above. Arrows and bolts can benefit not only from wood materials (C), but also metal (B) - however a blacksmith has to be the one who adds the material.
Hirelings
You can pay by the hour - 10 gp per hireling to increase productivity. Whilst using hirelings, each hour counts as more than one - the amount is 1 + the amount of hirelings in employ. In order to acquire hirelings you have to be in an area of the world that would afford you such individuals.

Crafting Professions
Alchemist - Potions and Poisons. Tools - Alchemist's Supplies/Herbalism Kit/Poisoner's Kit.
Blacksmith - Can craft items that are made with metal (Weapons/Armor/Shields and can make +1/+2/+3) - can also make jewelery and metal furniture. Tools - Smith's Tools/Jeweler's Tools/Tinker's Tools.
Carpenter - Items that are made from wood (Staves/Bows/Arrows/Shields and can make +1/+2/+3) - can also make wooden furniture. Tools - Carpenter's Tools/Woodcarver's Tools.
Enchanter - Imbuing non magical items to have magical qualities. Magical class required.
Leatherworker - Items that are made with leather/hide (Armor/Shields and can make +1/+2/+3) - can also make regular clothing and leather/hide furniture. Tools - Leatherworker's Tools/Weaver's Tools/Cobbler's Tools.