How do I create and reuse a document template?

Yes — that's exactly what templates are for. Prepare the document once — placement of signature fields, initials, dates, signer roles — then save it as a template.

On later sends, you start from the template, fill in only the signers' details and send: the fields are already positioned. It saves a lot of time on recurring documents (NDAs, standard quotes, service agreements) and keeps all your envelopes consistent.