I have two kids with sensitive skin, so I make their laundry soap. This recipe comes from The Handbook of Vintage Remedies by Jessie Hawkins.
Gentle Baby Laundry Soap
1/2 c. borax
2 c. baking soda (one 16 oz. box)
1/2 c. liquid vegetable soap
15 drops lavender oil (opt.)
1 c. distilled water
Mix all. Sometimes I use my hand to break up the chunks of borax. Instead of adding lavender, you can use lavender liquid soap. A couple big scoops with a tablespoon is enough for a large load.
Here is Jessie's website, Vintage Remedies. Go there for more great tips and recipes.