Witch Hazel comes in a water-like solution. You can usually get it at the pharmacy. Keep it in the fridge and put it on a maternity pad. Great for cooling relief after birth.
Arnica comes in mouth spray, tablets and cream. You CANNOT put it on any broken skin so best to go with tablets or a mouth spray. Take it during and after labour to help speed the healing process. It is supposed to help with muscles and bruising.
Tea Tree Oil is antiseptic, and stings if applied directly. It is strong, so needs to be diluted ideally. A few drops in a bath is good post birth for any abrasions/tears or c-section wounds.