Start with a real workflow
Consider a small client portal: a customer submits a task, an administrator reviews it, and both follow progress. Before choosing a framework, describe who can perform each action and what information they need. “Users can upload files” is incomplete until file types, ownership, size limits, and failure messages are defined.
Make completion observable
Write acceptance criteria around outcomes. A submitted task should remain after a page reload, appear only to the correct customer, and show a useful confirmation. Include the unsuccessful paths: a lost connection, an expired session, or two people editing the same record.
Deliver one complete slice
Build a narrow workflow across interface, validation, storage, and permissions. This reveals integration problems earlier than completing every screen before connecting the database. Review the result with someone who will actually use it.
Prepare the handover
Record deployment steps, backup responsibilities, and how errors are investigated. Keep a short list of known limitations and a way to reverse a release. A useful first version has a clear boundary: it performs the agreed work reliably and makes the next improvement easier to assess.
Try this: Select one important workflow and write three success criteria and three failure scenarios before adding more features.