You will need;
-Muslin bags (If you dont care to make your own, you can easily find these on line, as they are carried by many suppliers).
-Lavender bud powder
-Colloidal oatmeal, fine
-A few drops of jojoba or an oil of your choice
You can make your own lavender bud, chamomile, and colloidal oatmeal. All you need is the flower and a mill, a blender, or a food processor to grind with. Make sure that you begin with a pesticide free flower bud and use only the flower bud for the lavender, and the flower head and petals for the chamomile. To make colloidal oatmeal, finely grind oatmeal. You can check to see if it is "colloidal" by putting some into water. If it floats, it is colloidal and you have saved yourself a ton of money! Just make sure that it is finely ground for your washbag.
Once you have all of the ingredients together, and made into the right consistency, combine them all together, and toss into a blender. Pulse it until it is well, and thoroughly mix. Then pour a small amount of it into the muslin bag. When using on a baby, you will want to soften the bag in the bath water first, then gently squeeze it over the baby. Then use the bag to lightly rub the baby. In fact, that is probably the best way to use it, even when it is on you and not on a baby.
When making one for yourself, you can add your favorite herbs. Just make sure that you study the indications and contraindications for those herbs. You can also add soap shavings if you wish to boost the cleansing and bubble power. Of course, soap doesn't have to bubble to clean, but if you want it too, then have at it!