The easiest way to wash your dreads is to mix a little shampoo and water in a bottle and wash your scalp with it. Then rinse well, wrap the dreads in a towel to soak up the water (no rub!) and then just let them dry on their own. Do not use hair conditioner or a hair dryer on Dreads and Braids please.
When you have only part of your hair braided, separate your hair from the set and wash, dry and style it as usual and dread with braids as described above.
This is easiest done by tilting your head forward so that the free part of your hair hangs down and the dreads are gathered at the back in a bundle or any other convenient way.