best way i know save game when you find one,and if i didn't drop ender pearl exit without save, till you get them, and i find them alot around sand plains only at night.

Hope this helps, all i needed was the end? trophy's but my corrupted the other day

No other sources for Ender Pearls. Only choice is to go after Endermen. Although I believe one or two can sometimes be found in dungeon/stronghold chests, but it's rare. Usually it's bread, saddles, etc.

Sometimes you see Endermen at daytime because they do not burn like zombies and skeletons do, but they only spawn at night or in dark areas. It's easier to find them at night in open areas such as in deserts and plains. When you see one in the distance, just look it in its eyes and it will come to you, so you won't have to get to him. Best way to increase the chance of Ender Pearls is by having a sword with the Looting enchantment.