Editing a contract is basically not difficult and you don’t need to be a lawyer to do it; they simply have more practice.
The «be-all and end-all» of contract drafting is whether the text is clear and understandable to all. A «worst case (scenario) approach» («Anything that can go wrong will go wrong») must also be a guiding principle. Contracts are not only concluded for sunshine, but especially for rain. It must be remembered that the contract must be clear not only to the parties, but also to third parties, as often it is not those who negotiate and draft the contract who will later apply it. In the worst case, lawyers and judges will also be involved in the contract. Finally, from a purely editorial point of view, I find it important in practice that points that belong together thematically (e.g. on payment methods) are found under the same title or in the same clause.
Since the initial situation for the conclusion of a contract, especially in long-term relationships, can change and this can lead to legal disputes, this circumstance must be taken into account in contracts with the agreement of a legal change management and an escalation procedure (s. chapter […] Dispute resolution and law enforcement).
Whether a contract is good or not is particularly evident when things go wrong. Therefore, when drafting a contract, one must ask oneself whether all worst cases and their consequences have been taken into account. For this reason, lawyers are perhaps also better at editing contracts, because they are confronted with worst cases on a daily basis and it is easier for them, as legal laymen, to imagine what could go wrong …