In the base game of Dragon Ball Z: Kakarot, odds are that players never really needed to farm for Z Orbs. This resource is so abundant that players probably got enough of them just by playing through the story and completing sub-stories. Anytime players found themselves short a few Z Orbs, they were easy enough to get by making a wish on the Dragon Balls or flying around and doing a few fights. The same does not hold true for Kakarot's DLC 3, however, as the player's main game Z Orbs don't carry over into this DLC story.
Future Trunks has a massive skill tree to fill out, as he has all of the skill he had in the base game as well as several new ones from the DLC. In order to unlock all of these skills, players are going to need quite a few Z Orbs. Since the story of Dragon Ball Z: Kakarot DLC 3 is considerably shorter than that of the base game, there also aren't as many chances to earn Z Orbs from boss fights and the like. Players can use these tips to get Z Orbs fast for Trunks, though.
There are three efficient methods that players can use to get Z Orbs quickly, and these all require the player to have beaten the main story of DLC 3 already. Those that haven't will need to settle with grinding Z Orbs the good old fashioned way: simply flying around and collecting them in the field and from random encounters. After beating the main story, though, players unlock both the Training Room and the Time Machine.
The Training Room is a great way to farm Z Orbs because it also doubles as an efficient way of leveling up. The catch here is that the battles here can actually be pretty tough. Players should endeavor to fight the highest level challenge they have, being sure not to take on an enemy that's more than five levels above them. Alternatively, players can use the time machine to get Z Orbs even faster. Simply go back to the last story battle against Dabura, defeat him easily with the power of Super Saiyan 2 and an overleveled Trunks, and profit from the vast quantity of Z Orbs obtained. This is definitely the most efficient method if players aren't also trying to level up.
Finally, players could also return to an earlier point in the story where the random encounters are five levels below or lower than the player. Super Boost into these enemies and they will die instantly, rewarding the player with Z Orbs and experience automatically. As always, be sure to have Community of the Gods maxed out when farming these, as this will increase the number of Z Orbs players earn from fights.
Dragon Ball Z: Kakarot is available now for PC, PS4, and Xbox One, and releases on September 24th for Switch.