Single dose in any potency and wait. But the higher work faster and deeper, so a 200c is good to start with. Let us know your progress. My experience tells me that if the patient recognises him/herself in the remedy, that it is usually the right one. So if it is not Nat.m. and you get no relief, no harm is done and you can then retake your case. With repeated doses of the lower potencies you will cause more changes, which then results in having to antidote. Such a procedure then gives you a changed remedy picture, as the original state is lost and prescription become so much more difficult.