DIY tank top - item: scissors, bleach, plain tank top/t-shirt. Dip dye the bottom of the shirt with bleach. Wash it out and let it dry completely. Then cut the part you bleached into thin strips and tie a knot at the ends.
How to quickly get a t-shirt to fit better. It is perfect for those work t-shirts that you get stuck wearing but are sized for someone twice your size. Fashion and Sewing Tips: RECYCLING OF SHIRTS AND T-SHIRTS - 2