When it comes to describing something that is typical or commonplace, there are plenty of synonyms for the phrase "most off-the-rack." It could be referred to as standard, average, normal, or typical. Another option is to describe it as bland, mundane, or unremarkable. On the other hand, if you want to emphasize that something is unique or individualistic, you could use words like one-of-a-kind, exceptional, or singular. Additionally, you could describe something as custom-made, tailored, or bespoke if it has been specifically crafted to meet a particular set of requirements. Whatever your preferred word choice may be, there are plenty of ways to describe something that is "most off-the-rack".