Ask either twin "Which path would your twin tell me to take". Then go down the other path from the one they indicate.

Reasoning:

If the twin you ask is the truth-telling twin, he will know the other twin lies and will point you in the wrong direction, so will point the wrong way.

If the twin you ask is the one who always lies, he will also point you in the wrong direction (the direction the truth-telling twin would NOT have told you to go in)
Yep! You and cathybogart got it right