There's probably not much advice here because you seem to already have a handle on it. Go slow and clumsy with your process before fine tuning your approach. E

There's probably not much advice here because you seem to already have a handle on it. Go slow and clumsy with your process before fine tuning your approach. Embrace some manual labour at first to provide yourself with a high quality validation set of docs which you can compare the performance of your approaches. (but be wary of your approach overfitting even your validation set as you tweak at prompts).