In my effort to keep three bikes clean and performing smoothly, it's necessary to have something at hand to wipe with. In the garage, hanging near my bikes, are two bags chucked full of rags. T-shirts work perfectly. I raid my own drawers for old or holey t-shirts. But that alone doesn't fulfill my needs as I tend to be fastidious. When the supply runs low I raid my children's dressers, extracting their too small, stained, or unfavored garments. Of course, that also leads to cleaning out their rumpled piles—a side benefit.
Also inside the sack are zipties, my oil can, and extra plastic flowers for decorating the girly bike.