Hope Van Dyke took a year long course focused mainly on postural correction, specifically in the pregnancy and postpartum population, but much of it can be applied to anyone.
There is very specific things to look for in posture. Some of these are: what expands when you breath, what tightens when you engage your core, where your hips are over your feet, pelvis position, shoulder position, thoracic and head position.
Then after looking at these and assessing mobility and strength you add in the perfect exercises with very specific cues to help recruit the muscles that will best improved postural control. Some common muscles that need to be recruited more are the deeper control muscles such as serratus anterior, transversus abdominis, glute med, glute max, hamstrings, latissimus dorsi, and deep cervical flexors.