Rather than interpreting single gestures, look for clusters of body language that tell a consistent story:

Open/Engaged: Uncrossed arms, leaning slightly forward, feet pointed toward you, nodding, relaxed shoulders.

Closed/Uncomfortable: Crossed arms, leaning back, feet pointed away, minimal facial expression, tense shoulders.

Interested/Attracted: Mirroring your posture, touching their face or hair, maintaining eye contact, tilting head.

Wanting to Leave: Checking phone/watch, shifting weight, angling body toward exit, shorter responses, less eye contact.