Airways you can are the trachea and the main-stem bronchus. Left main-stem comes out at sharper angle than the right. This is why people aspirate to the right lower lung and ET tubes are often placed in the right main-stem bronchus if advanced too far.
Tracheal deviation away from pathology indicates positive pleural pressure shifting the trachea contralaterally. This may occur with large pleural effusion or tension pneumothorax
Tracheal deviation towards pathology indicates negative pleural pressure that deviates the trachea towards pathology. This may occure from collapse, lug resection, or scarring of the lung or pleura.
On inspiratory film, you should be able to count 9-10 ribs
Smoothness or contour of the enlarge mediastinum may point you towards various pathology. See below the smooth contour in pulmonary hypertension in contrast to the irregular borders seen in sarcoidosis.
Lateral films can give lots of added information and should be obtained when able. The mediastinum can be broken down into three compartments: anterior, middle, and posterior.