Leave the hotel room with "Do not disturb" sign: Reflect if you really need new towels, new sheets, new shampoo bottles, new earbuds and other hotel goodies. Taking a break from these or even avoiding some of the waste is a great contribution.
Hang your clothes.
Further, try to air dry your cloth on the line instead of tumble-drying it in a vented dryer. This can completely remove the impact of the dryer. 5% of all electricity used in U.S. homes is used to dry clothes.
Use cold water.
Most of the time, unless they are very dirty, there is no need to wash your clothes above 40°C. It also helps to release less microfibers into the water and the ocean, and pollute less.
Consider energy guide labels.
If you need to buy a new home appliance or consumer product like asking machine, Fridge or TV consider the energy guide labels and choose energy efficient appliances.
Hang it up while showering.
Irons are one of the most energy consuming home appliances. You can avoid to irons by hanging them into the bathroom while you are showering. Steam will help to reduce wrinkles.
Most of the clothes we wear nowadays contain plastic and synthetic fibers. Each laundry wash bits of plastic (microfibers) can escape into the ocean which cause incredible damage. You can use the Cora ball or washing bags like "Guppyfriend" to help with that.
Give old clothes a second life.
Reuse your old socks, t-shirts and fabrics as cleaning cloth at your home. Most cleaning cloth are made of microfiber, polyester or other polymers, which are very hard to the environment because they are super difficult to recycle and often impossible to biodegrade.
Wrap your water heater.
For just a few dollars, you can wrap your water heater in a heat blanket, saving cash and reducing carbon emissions.
Use dryer balls.
Dryer balls will fasten up the drying process, soften clothes and reduce static. But don't go the fabric ones as they are richer in toxin, last less and often one time use.
Efficient products / appliances.
If use old appliances a lot they might consume way more energy then modern appliances. Look for ENERGY STAR qualified products and pick the model that uses the least amount of energy possible.
You can use desktop research to compare energy providers in your region. Often times there are more green alternatives available for not more money. It's a single action with incredible impact in the long-run.
Switch off electronics.
10-15% of the electricity consumed at home is used by appliances in standby mode. Especially TV, radio, computers, microwaves, dishwasher. Unplugging them or turn off the central switch. Smart home systems can help to make that process easier.