Tank Girl's pants and legwear are pretty open to interpretation. We've often seen her with tall socks and ripped stockings, workout shorts, cutoff jeans, baseball pants, and chunky lettered belt buckles.
Use what you can find and try to anticipate the weather for your occasion. You can also add details like dirt, bandages, knee pads, garters, etc.
The right boots are essential for this costome. A lot of other features can withstand plenty of artistic license, a pair of iconic combat boots are mandatory for Tank Girl. Pictured above are the Kathleena Strap Calf Boot by Dr. Martens.