Buy fashion made from sustainable materials: cork, latex and jute... Jute is hessian. This is quite difficult but a simple Google search will yield ethical and sustainable brands like El Naturalista who believe that
"Naturalistas" start their journey observing everything that surrounds them. They travel through the world and observe it, becoming impregnated by its textures, its colors, its lines... and after a thousand journeys, real and imaginary, they discover that a single idea brings us together. Whatever our race or culture... we all walk in search of happiness.
Another brand to consider is The Simple Shoes who use recycled materials in addition to sustainable ones. They use recycled rubber from inner tubes in big tyres, like on a tractor I suppose, to make your shoes.
Another way to buy sustainably is through second hand clothing either via opshops, on ebay, in vintage clothing stores or via clothes swaps. There are a lot of options for second hand clothes and these days the clothes you buy are generally freshly washed and in perfect condition.
What else can you do? Make like it's wartime and mend things that no longer fit.