This is a very ACTIVE pose. You should feel as thought you are radiating healthy effort.
The foot on the ground should be rooting in but also pushing away. The back foot should mimic that energy as the leg reaches out parallel to the floor.
The pelvis is parallel to the floor. Often the hip on the side where the foot is raised, tends to tilt up. Push the elevated side down toward the floor. This may mean the back foot gets lowered a bit.
The belly is pulling toward the spine as the spine lengthens.
The arms reach forward, parallel to the floor. Triceps turn toward the face.
Bring the head gently up to gaze in front of you, but be sure not to compress the back of the neck.
If this is too intense the arms can also come straight out to the sides or run along the side body.