I started making my own laundry soap 6 years ago. We love it and I hope this video helps you.
To Make Liquid Soap
1 bar ivory soap
2 cup borax
2 cup washing soda
Shred the ivory using a cheese grater, place in a pot with some water and melt over low heat.
Pour the borax and soda into a 5 gal bucket, add hot water and stir to dissolve. Add melted soap mixture, stir and fill up the bucket the rest of the way.
I use 1 cup per wash load.
To Make Powdered Soap follow the same steps as above, but do not mix with water. I use 2 tbs of powder in my top loader and 1 tbs in a front loader. Adjust the amounts to suit your water type.