How can I better hunt Endermen?

Solution 1:

Attack their legs, never look at them.

If you don't look at Endermen, they seem less-inclined to teleport away.

Here's a video example:

Solution 2:

If you can already make potions, do the enhanced instant damage potion. Throw in his direction without looking at him. If he doesn't die on this one, hit his legs – don't look at him, especially not his face.

Another method (easier) is to equip a bow and shoot from large heights. You have to aim a bit over his head – be sure not to aim the crosshairs at his head. That's how I got my 12 pearls.

Solution 3:

The easiest option is just to wear a pumpkin as a helmet. Although this disrupts your view, Endermen won't teleport away or attack you when you look at them.