Here's a very simple recipe for homemade fabric softener.
1/4 Cup Baking Soda
1/2 Cup White Vingar
Fill your machine with water
Add the baking soda then clothing
During the final rinse cycle add the vinegar (pour into the softener dispenser if your machine has one)
If you have a front loading machine like I do poor your detergent into the front of the machine with the clothes and then put the baking soda into the tray where you'd normally put the detergent and then follow step 3)