Many accessories are upgradable, often following the path of Talisman → Ring → Artifact. An example of this is the Feather Talisman, the Feather Ring, and the Feather Artifact. The upgrades of each accessory are often found within higher tiers of the same collection, and the crafting recipes usually require using the lower tier accessory to craft the higher tier accessory. These upgraded accessories often provide the similar bonuses, but more effective, and of a higher Rarity.
Note that if two of the same type of accessory are held (ex: a talisman and a ring), only the effects of the best one will count. For example, if Feather Talisman, Feather Ring, and Feather Artifact are all held simultaneously, only the Feather Artifact's reforge and ability will count.
Since the Reforge Update, only the Unpleasant reforge gives Crit Chance, so set the reforge to Unpleasant if you have a low Crit Chance or reforge your armor to pure and talismans to hurtful.
The Accessory Bag is unlocked in the Redstone Collection and is located at the bottom right of the SkyBlock Menu. Placing accessories in the Accessory Bag will allow their effects to work as normal while saving inventory space with the exception of the Piggy Bank's ability.