I found this DIY recipe here. It was a starting point for me, but I tweaked it a bit because it seemed to work a little better. You will first need:
6 Cups of Hot Water, 1&1/2 cups White Vinegar & 1 bottle Suave Conditioner (your favorite scent). I used Lavendar.
Pour your hot water and bottle of conditioner into a small pot. Bring to a boil and stir until competely dissolved. On The Frugal Girls site they just mixed everything together until it dissolved, but I found that if you boil your water and conditioner together first it mixes better.
Stir in your vinegar. Mix well.
Pour into empty fabric softener bottle or milk jug or whatever you have on hand. Use 2 tablespoons per load during rinse cycle or pour into your downey ball and throw in the machine. I've been using this fabric softener for a few weeks now and I really like it. Plus it's so easy to make and so much cheaper then buying it in the store. I think the conditioner cost $0.98 and I had the vinegar and water on hand. So for an average price I'd say maybe $1.50-2.00!! You can't beat that for fabric softener. Let me know if you give it a try.