Something im surprised isn't in the game but im sure could be done. Everyone has materials filling up their bags at the moment with no real use for them ie armor and weapon parts. These could be used as base ingredients along with the collectable spin metal, spirit bloom etc maybe along with a new rare material drop. They could be used for either creating new gear or just upgrading existing gear. Wether its improving stats, swapping or adding a new perk maybe even changing the appearance in some way. Perhaps even creating consumable items to give stat buffs like speed, damage, health. It would be an ideal use for glimmer too which at the moment is fairly useless other than to purchase ammo.