In general we use Xander's guide rules for magic item crafting, but for now I am going to restrict item and potion crafting to level 10+ Artificers, and scroll crafting to level 10+ Order of Scribes Wizards except for narrative driven exceptions.
However, with regards to item cost and rarity we use the much saner Sane Magical Prices house rules.
Crafting for most items can happen aboard HMS Lady Jezebel, unless the item in question is especially large (like a golem). However there may be risks associated with that.
Magical item blueprints and recipes are generally obtained either by copying the blueprint from a library or by purchasing it in a marketplace. Occasionally blueprints can be directly taught from someone that already knows the blueprints.
Also DM caveat, the D&D rules for this are a bit "DM optional" and not all that well fleshed out, so if things start to get unbalanced I reserve the right to take action.