Whats the best way to find and kill endermen in minecraft

An Enderman's strategy is to teleport behind you and attack. Making it impossible to attack it. So what you want to do is build a two-block high wall with a width of two blocks then walk to the wall with your back facing it. This way it can't sneak attack you from behing. Then as long as you're in front of the wall then the Enderman should be as easy as killing a normal mob. This is the same for bedrock edition so if you switch the same rule applies.

You could trap an enderman in a boat, since they don't teleport away when in them last I could recall.

Just place a boat next to where the enderman is standing, push it onto the boat (while not riding the boat), then it could get on the boat, then start killing it.

Since it's intentional that mobs can ride boats, this would technically not be a glitch or exploit, though at this point it's up to your preference if you'd still want to consider this legitimate or not.