This is more of common sense as it's basically this one : [Release] WoW ObjectDumper/Radar combined with 400g a hour! By farming clams!
Simply go to Winterfin village, start up radar, enter notification tab, put in "winterfin clam" (there are many winterfin mob so clam is important or you'd get false reading), switch to radar, set it to stay on top, and you can start finding every clams quick and easy. Siren's Tear still go for around 200g on AH.
If you're a 77+ druid with cold weather training, you can farm even faster since you won't get shifted out of flight form and you can loot most clams without pulling aggro.I did almost 400 clams in 1 hours, that is 4 siren's tear or about 800g per hour as druid with radar running. It should be noted that siren's tear has a respawn timer (uncertain of exact time currently), so don't go farm crazy as it'd take a while to clear out clams you farmed.