As well as washing at a lower temperature here are a few more tips for making your washing habits more environmentally friendly:
Wait until you have a full load (or use half-load option on your machine if it has one).
Maintain your machine so it lasts longer – don’t overload, clean filters, empty pockets before putting things in!
Wash less often – your clothes might last longer too!
Avoid tumble dryers if possible – they are very energy intensive.