Okay, i just finished to gather my plunder and wanted to share with people my metod since could be useful for others, it took me like one hour, this can change according your luck with the missions you get or if players try to erase you before finish them
What i did was only focusing in the missions that you get at the start of every match, each one rewards you 250 plunder
the best zone in my opinion is the pirate ship at the bottom of the map on the left corner since has a lot of chest, 4 rares and some mobs and the torment arrive very near the area so you can easily run to it after you are done with your quest, i rarely see players there
YOU CANT FLY OVER THE MOUNTAINS, you must fly on the path that can be easily seen on your map, you cant miss it, from there you have 3 options
dive on the ship, there is always an elite
dive next to the house on front of the ship, there is an elite too
dive on the path between mountains, there is an elite too but this one is tricky, since you can fall on the branches of the tree and miss it even if he is right under the branches
also very important tip is notice if there are parrots of other players leaving the area, after a player land you can see a parrot flying away, if you see one coming out of the ship then a player went there, keep in mind this to decide where you land, and remember your parrot land insta kill any npc, so try to land on elites when you can
the worse missions you can get are the one of get an item, these can be incredibly rare to get sometimes, important not mistake them with abilities, items are barrels for example
the one of get abilities is also kinda hard but easier than an item in my experience
the one of chest only is hard if other players land on the area and are also farming chest
from there all are easy like gather 30 plunder or kill 10 mobs, even the one of kill rares is very easy since they appar on your map and are very weak at lv 1
thank to good this is not so grinding like the first one, but still terrible, so if you only want the rewards i suggest you do that
also remember you can take it easy andget like 1000 plunder with the daily mission, which is just finish the mission you get for the match, one of the missions i mention above
hope it help you