Piles in is an expression used to describe the act of adding or accumulating something in a haphazard or disorganized way. Antonyms for this phrase can include neatly organizing or decluttering. Rather than piling in items, one could methodically arrange or carefully place them. For a space overwhelmed with clutter, one could remove items, tidy up, or streamline. Essentially, the opposite of piling in is taking a more intentional and clean approach. In summary, the antonyms for piles in are organized, decluttered, intentional, and streamlined.