Under the right conditions, nothing catches more fish than the versatile and lively leech
For most presentations, I run the hook through the leech’s tail where the sucker is. That allows the leech the most movement as it swims headfirst, away from the hook. Sometimes when I’m fishing vertically, such as lifting and suspending a jig off bottom or using a slip bobber, I’ll hook the leech in the middle of the body instead. That creates a different look and motion that can also trigger fish to bite.