crafting equipment and jewelry

How do I get the recipe for crafting equipment and jewelry?

 

If you're referring to unique items, either to build your own copy of a Parallel World item or items associated with events, check the crafting achievements tab within the Journal window. You'll find that for most of these recipes you'll need to kill the related boss 100 times on any variety of difficulty levels (if I recall correctly, any level except Normal). If the boss appears in both Normal World >and< Parallel World dungeons / boss rooms, you can kill a mixture of either version of the boss to earn the recipe.

There will be other ingredient requirements in the recipe. That usually includes the appropriate Parallel World ring, junk equipment of the same class (i.e., if you're trying to build a special chest plate, you'll need to include a random chest plate in one of the four crafting slots on the workbench), and raw materials (e.g., ore) which you'll have to farm separately. 100 units of the boss' kill drop is also usually required for the craft; here, you'll need 100 units dropped at the same difficulty level. So, you could kill Arachna in Normal World boss room at Painful difficulty 80 times + 20 times in her Parallel World room on Bloodshed and you'd earn the recipe, but you would have to kill her 20 more times on Normal World Painful or 80 more times on Parallel World Bloodshed to end up with 100 units for the crafting ingredient.