Much of what you can do for the environment revolves on how you manage your clothing!
Buy fewer clothes. Remember, they all come from either agricultural sources (cotton, linen, wool) or oil-based ones (polyester, rayon), so a savings in either category has a tremendous ecological benefit. Buying less means less land scoured with conventional farming practices, less oil consumed and fewer toxins released. Shop instead at thrift stores and deck yourself out in retro style.
Since agricultural items grown for clothing are not eaten, there are much fewer restrictions on pesticide use. Cotton uses approximately 25% of the world's insecticides and more than 10% of the pesticides.
I feel spoiled that I now have 2 pairs of jeans. A few shirts and a few pants are all you need. I am sympathetic if clothing is your passion, but get creative with accessories and be honest about the fact that much of your wardrobe sits unused in your closet. Donate what you don't need to thrift stores.
Appliances account for 17% of household energy use, and aside from your refrigerator, your washer and dryer are the biggest consumers!
Wash your clothes less often. A day at the office does not require a thorough wash in heavy-duty laundry detergents! Hang them up to wear again (socks and undergarments excluded, of course). Each time you wash clothes, you use water, put detergents into the environment, increase the demand for plastics (containers) and use energy to power the machines and heat water. The best way to save on your laundry footprint is simply to not do laundry! You will also enjoy the added bonus of having more free time as you spend less in the laundry room.
Avoid clothes dryers! Just hang them up to dry. I have a large drying rack which takes care of business, and most items are ready within 24 hours. If time is an issue, I have found that running a regular fan pointed toward the hanging clothes speeds up the process with minimal energy use. If you are really ambitious, put them on a clothesline outside. The sun is a natural bleaching agent, so it can help you avoid the chemical variety of bleach. I only use the dryer when I am in a true hurry or occasionally as some items need to be fluffed and de-linted.
While we're at it: Avoid bleach. Unless you're washing hospital garments, it is just unnecessary and harmful to you and the environment.
Use energy efficient appliances. They conserve water and use a more concentrated detergent (reducing the amount of plastic container waste). Some dryers don't even use much heat at all, so they are a much better option than traditional varieties.
Wash in cold water. You will save on your hot water heater by using less energy and probably save your clothes from the stress of getting washed in hot water.
Use natural laundry detergents. They all seem to work just fine for me, and many smell great. You'll be saving on oil and phosphates from the environment, decrease your carbon footprint, and keep those toxins off your skin. In addition, consider using a smaller amount of soap. A lot of people use way too much!
Taken together, these steps are not very hard. Too often, we don't think about our clothing choices when we consider environmental stewardship. But everything from making clothes to maintaining them produces a significant strain on the environment. Keeping a simple wardrobe, washing it minimally and using natural cleaners can have a substantial environmental impact and help simply your life, too!