Try to wash only when you have a full load, using eco-friendly detergent (try using powder from a recyclable cardboard box or an HDPE bulk container. You can also refill from bulk stores), using cold water cycles as much as possible.
Dishwasher detergent, lemon or hydrogen peroxide work great on stains.
Dry on a line when possible. If you use a dryer, compost the dryer lint and forgo dryer sheets (ideally you should avoid wearing synthetic static clothes anyways).
Ironing: Iron very few things only and use homemade starch in a stainless spray bottle.