To Steal the Stolen Lands
For the purposes of this game, there are no magic item crafting feats. Instead, any PC with a sufficient crafting skill can attempt to craft magic items – this requires gathering material supplies, possibly finding or creating a special location, and making a crafting check to create the item.
Scrolls may be scribed by any spellcaster for the cost of scroll creation, no skill check needed.
Potions require a Craft (Alchemy) check, knowledge of the spell effect you want to create (Use Magic Device can be used here as a substitute), and a crafting check with a base DC of 10, plus 5 per spell level.
All other crafting begins with a base DC of 20, to mark that the magic item must be masterwork to be fine enough to contain the magic, with an additional +5 to the DC per spell level (for wand, staves, rods, and wondrous items that don’t give specific bonuses) or +1 bonus or equivalent effect (for weapons, armor, and items that give a +1 or more.)
Items with an effective +1 or +2, or which contain spell levels 0-2, only need special materials, thematic to the item to be created, in order to create them. Anything more powerful than this will require a special location, either discovered and secured for the purpose or specially created from exotic materials.
As an example: a +1 frost longsword requires blood from a cold-subtype creature to quench it in as a creation component. It can be made in a regular forge by a sufficiently skilled and careful smith, with a DC30 skill check.
A +2 frost longsword, however, needs forged in a location of supernatural and eternal cold, with something like ‘coldfire’ in the smelter. This location could be the heart of an ancient glacier, or a room made from ice in your keep, with the bricks of ice mortared together with the blood of a white dragon.
On the extreme, something like a +5 axiomatic holy keen longsword – total bonus of +10, and therefore a DC of 70 – isn’t just something you could knock together a chapel to forge it in with a few pints of holy water; even if you’ve made a place so sacred to the powers of Good and Law that stepping inside burns the wicked, you’ll still need ingredients like iron mined from the seven peaks of heaven, water personally blessed by an avatar of said Powers to quench the blade in, and blood from an angel who willingly gave their essence to help forge such a mighty holy weapon.
Giving a name to magic items that you craft is encouraged, and may result in minor special effects and the occasional bonus, as in naming it you essentially are making it a minor (or possibly major, for sufficiently powerful items) artifact.