Hi Kel: Here are a couple of things you can do:
Pour the vinegar into a large bowl. Add your essential oil, if using. Add your baking soda. When fizz has settled, pour into storage container of choice. Use up to 1 cup (depending on load size) per load. I poured mine right into the regular fabric softener location.
Mix hot water and conditioner together in medium bowl. (The hot water helps smooth any clumps from the conditioner). Mix in vinegar and pour in container of choice. Use the same amount as you would a store bought softener and add to the regular softener spot in your washer or during the rinse cycle. Note: I used a regular cheapo conditioner from the dollar store. The higher quality conditioners won’t make any noticeable differences, so don’t waste your money!
Here's a link with several recipes:
Mix 6 cups hot water, 3 cups white vinegar and 1 cup of hair conditioner. You can buy the hair conditioner from Dollar Tree. It's used for the smell so pick one that you like the smell of. Store this fabric softener in a bottle with a lid.
I actually use wool dryer balls instead of fabric softener. Making your own wool dryer balls may seem complicated, but this is a simple step-by-step tutorial. They are so much safer than chemical softeners or dryer sheets, and they work really well. Hope this helps! Hugs, Holly
PS - We have a FREE eBook with recipes for all of my homemade and all-natural cleaners. You can download it here --> https://pinkfortitude.com/thank#GreenClean
Here's a great post on making fabric softener.