This will come naturally during regular gameplay.
If you wish to boost the achievement the quickest method would be bringing an item to the trial. Equip the perks “Built To Last” from Felix Richter to replenish charges to an empty item once per trial and “Plunderer’s Instinct” to locate item chests within a certain range to quickly locate new items in the trial.
Additionally you can burn a “Tarnished Coin” or “Shiny Coin” offering to spawn respectively 1 and 2 extra chests.
If you are boosting in group have everyone burn a “Coin” offering, bring in an item and equip “Built To Last” for maximum items, chest spawns and charge replenishing.