The phrase "giving the once-over" is typically used to describe a quick or cursory glance at something or someone. Antonyms for this action might include "studying closely," "examining thoroughly," or "scrutinizing intensely." When someone takes the time to study or examine something in detail, they are able to gain a deeper understanding of its qualities, characteristics, and nuances. Conversely, giving something the once-over suggests a lack of attention to detail, which can lead to oversights, misunderstandings, and missed opportunities. By taking the time to study or examine something more closely, we can gain a better appreciation for its true value and significance.