Wash less, wash delicately
Only wash when you need to and your clothes will last a lot longer. In general, try to wash in colder water as heat tends to break fibres down. Try not to exceed 40 degrees celsius.
Avoid tumble drying
Not only does tumble drying expend a lot of energy, it damages your clothes too. Try to line-dry whenever possible. Also, avoid drying in the sun as it can cause your colour to fade faster.
Iron with care
Ironing your clothes can actually help preserve them in the long run as it ensures no permanent creases develop. However, always be careful about using the right heat setting for the right fabric. When in doubt, always read the wash care instructions.