These can be found in chests throughout London or by completing activities such as Train Robberies, Cargo Hijack and Boat Raids.
When crafting your gear you can craft Weapons, Gauntlets, Capes (Evie) and Belts (Jacob).
You can craft upgrades for things such as your bomb pouch, medicine pouch, knive pouch and upgrade items such as your smoke bombs and throwing knives.
On top of gear and personal upgrades, you can also use crafting resources to upgrade your gang. These upgrades are broken down into three categories:
Which is all about intimidation and getting extra items (loot, carriages and deliveries) on the streets.
Which is focused on improving the Rooks as well as sabotaging the Blighters and Templars.
These will be all about getting you discounts when you purchase items and will earn you more money which will go into your train's safe.
It looks like some gear requires special resources. How do I earn those?
Some items require special materials such as Golden Spider Silk or Fire Opal before you can craft them. These materials can be earned by completing certain missions, levelling up your scavenger skill to raise your chances of finding rare materials in chests or by increasing some of your associate's loyalty levels. Ned Wynert, in particular, will reward you with rare crafting materials when you complete certain types of side missions.