#1: Soak stains immediately. When you get a stain on something, you have to deal with it immediately. If you let it dry, it's permanent. 

#2: Learn how to sort. You thought it was just about whites, darks, and delicates, but your clothes will wind up much cleaner if you separate them not just by color, but also by fabric type and water temperature. And to prevent lint from spreading, separate linty fabrics like towels, flannels, and sweatshirts from corduroys, permanent press, and other smooth fabrics that can pill.

#3: Don't overstuff. You want to wash full loads only so you save on water use and energy consumption, but you don't want to fill your machine so much that your clothes can't get clean. High-efficiency front loaders can hold up to 20 pounds of clothes, but top loaders max out at about 16. 

#4: Add soap, then stuff. Before you add your clothes, add your detergent, allowing it to dissolve in the water fully before adding your clothes. Your soap will work more effectively. I love Tide Pods and the new Gain Flings laundry detergent, so easy to use!