Look, the crafting is actually really simple, and anything deviating from this is a mistake on my or someone else's part.
Every item has a Mat Level, That is equal to 2 times the number of unique traits, and then add the average of the total Trait levels.
So if it has Level 3 holy trait, and nothing else, it is 2 (Only one unique trait) + 3 (Total Trait levels) which means the item has a mat level of 5.
All crafting is 3d6+Stat verses 3d6+Mat Level
The higher your roll is, the better quality your work is, the higher the material's roll, the harder it is to work with.
You either want yours and the material's roll to be high (The material was tough to work with, but you did it well, for a high quality, high difficulty project) or for the material to roll lower than you by far (Your skills in tandem with the material's ease of manipulation lended itself to your craft being high quality.)
If the material beats you, any number of things can happen, which is determined on the spot, considering the infinite possibilities.
Traits are basically Perks for materials, if you have two or more instances of the same trait, they have the potential to stack, increasing that Trait's level
If you are wholly uninhibited, Boss Souls you have absorbed have a chance to apply effects to any craft you make, this lends itself to fun things happening, like a glass bottle catching on fire permanently, or an enhanced sword suddenly being made of a different material, this is based wholly on the boss soul absorbed, and if you don't like it, you can purchase a Badge to restrain that effect from your crafting when worn. this is how enchanted item crafting works.
each stat has a different effect on crafting, so different classes craft differently.
Int is using your intelligence to craft, meaning you just do it as intended, with no extra traits from your method, this is the default crafting stat, due to people good at crafting and people good at other things do not necessarily have to be the same thing.
Health crafting mean you do it quickly, and if the materials are dangerous, you may hurt yourself in your haste. this can be done in combat, but it is hastily made, adding that tag and limiting it's effects, so full items cannot really be made in the heat of battle, but something like a bomb strapped to an arrow can...
Stamina crafting is where you make a simple object and repeat that as many times as possible, it is the monotonous crafting, for stuff like making 20 bags of rocks or something similar.
Dex crafting is mostly to do with stuff like Binding things in hide, Sewing them together, or generally using your nimble and experianced fingers to do the job effectively, but the result is a bit Rough, and gains that tag.
Str crafting is where you take the biggest rock, Stick, and rope, and tie them together as hard as your muscles allow, So the result is naturally Crude, and gains that tag.
Agility is similar to health, but your health will always be higher than your agility, usually, so only use this if you are very very quick, or the materials do not have damage associated with them. Same method, you can use this in battle, for MacGuiver styled creations on the fly.
Basically, Since you have a specific job, Class, and goals, you should only really know one or two of these, 3 if you are planning on doing it religiously.