If you have a spare slow cooker and immersion blender, you have just about everything you need to make your own soap. The simple project takes just an hour, and you can customise your bar of soap with any essential oils or fragrances if you so desire.
The One Good Thing by Jillee blog offers a photo tutorial of the process. Besides water, the only ingredients you need are olive oil, coconut oil and sodium hydroxide from the hardware store.
You will need to take special care when handling the sodium hydroxide; work in a well-ventilated area, and wear gloves and glasses. (You don't want to reproduce any Fight Club-like scenes.) Also, it's best not to do this with a slow cooker or blender that you're going to cook with afterwards; you can find inexpensive slow cookers at discount stores or online auctions.
Once you've gathered all your materials, you just need to weigh the ingredients, toss them in the slow cooker, and an hour later you have wonderful bars of soap.
How to Make Homemade Soap in a Crockpot [A Photo Tutorial] [One Good Thing by Jillee]