The starting point is the full decision, proof of service, previous applications, earlier decisions and documents on the personal situation. Depending on the topic, medical records, family documents, residence cards, employment confirmations or translations may be added.
A short chronology is important. When was something applied for, served, answered or supplemented? This sequence helps identify open deadlines and possible gaps.
Documents should not be collected at random. It is better to arrange them by operative point, evidence topic and date. This makes it easier to see which arguments are already supported and what is missing.