
I would think you're being very successful already - although I trained my dog to "poo" in one place by just letting weeds grow there and hiding one or two biscuits in the long grass!! But to be fair, my dog is 4 (rescue dog) so maybe he is more switched on than a pup (I'm assuming your dog is a pup). I can always tell when my dog is going to "do the stuff" so I just wheech him into the right place and after a few of those he realised where was the right place to do the toilet. You haven't made any mistakes - when you go outside with your dog I would just guide him to the place, treat him and when he performs treat again. If he tries to go elsewhere guide him back, if too late - no treat. They learn!! Hope it helps.
CG