Best way to get featured raid's red borders?

[full pier]

What's the best way to get the patterns from featured raids? I farmed nez last week and the drop rate felt really poor, so is there a better way? Thanks

[worldly hemlock]

you do the redboarder run (aka do a full run and get the redboarder chest puzzle)

then farm the encounter that drops the weapon you are after

there is plenty of loot tables if you google for them