The very easy & some what evil way is quicksand & a wooden golum, make a 9x9 or 11x11 room, make it 6 blocks hight or 7 if 2 layers of Qsand, place the Qsand 3rd block up fill layer leaving a hole in centre for shard/cage, now you have a layer of Qsand & 3 block space for endermen to spawn on, place the cage & ss just above the hole in centre & hook up an on/off stitch use RS wire if its in your pack or pipes pipe wire & gates, or even a simple lever on the underside of cage, now place a chest in centre of whats now the lower half of this grinder attach the golum to chest & turn on the grinder, endermen will spawn on the Qsand & slowly die while falling the golum will pick up drops & put in chest, just remember dont jump
, there are other ways to go about this, the best one I came up with was a layer of Qsand as the roof glass floor with 2 block space for spawns, the cage & SS in centre with on off like last time, but in the glass floor near centre place an ender chest & the golum, under the glass floor make sure you have no more than 2.5 blocks or mobs could spawn there, this is the viewing gallery. very very simple builds but with a t5 10 minutes gets a lot & I mean a lot of pearls.
also note that snow blocks or a water curtain as walls works well too, endermen do not like water at all, there are many ways to make grinders droppers, crushers, stepped piston traps with turtle at bottom, all works just as well, but this way the build cost is very very low, the hardest part is finding the quicksand, plus its evil & thats a bonus in my book.