Start with the question, not the features
An MVP answers a question about your business. Define the question first: is this a demand test, a usability test or a technical feasibility test? The scope follows from the answer.
Map one user journey
Pick the single most important user journey. Build that end-to-end before adding adjacent features. Adjacent features belong in a later release.
List assumptions explicitly
Record dependencies, unavailable data, integration access and business decisions. Give each assumption an owner and a validation method.
Define release evidence
Agree functional acceptance, permissions, test coverage and operational handover before development begins. Keep later features in a separate backlog.
Make it specific to your situation.
Use this guide as a starting point. The next useful step is to record the real context, identify the decisions that need an owner and agree what evidence would support the decision.