The term 'They're On Top of Things' can be solved by the crossword solutions of 'COVERINGS' (9 letters) and 'LIDS' (4 letters). COVERINGS are materials used to cover something, such as fabric, paper, or plastic. LIDS are covers that fit over the top of a container, such as a jar or pot. Together, these two solutions suggest that someone is organized and on top of things, as they have the necessary COVERINGS and LIDS to keep their belongings in order.