I use essential oils in my laundry daily. I put about 10 drops in the soapy water while its filling. Some oils are dark in color, so I use those in dark loads, & light colored oils in my brights. Its worth spending the money for true essential oils, the fake ones have chemicalas that can ruin your fabrics.
You can make the essential oils without a still, they aren't as strong, but they work great for our family :) I found a website that has instructions that are pretty spot-on to how I do it, & its very simple: www.ehow.com: How to Make Essential Oil
These instructions are how I make them. I like to use almond oil, but have used olive oil. We have an organic farm, & I have a special herb garden planted for crafting & culinary purposes. You can also get fresh herbs at your local Farmers Market. I also use old ice cube trays, put my fresh herbs in them, poor a bit of water over them, & freeze. You have fresh herbs even in Winter! Happy Crafting! BTW - I get many of my supplies for crafting from: http://www.brambleberry.com/