Abstract progress is difficult to assess. A visible piece of work gives you and another person something specific to inspect. When a project stays permanently in preparation, choose a small usable object to produce.
That might be one completed example, a rough prototype, a written decision or a page someone can follow. Choose a form that tests the project's main uncertainty. A beautiful title slide does little to test whether the reporting method beneath it works.
Expose the important weakness
In a fictional training project, produce one lesson with its exercise and answer explanation before planning twenty more. Give it to an appropriate willing reader. Watch what they misunderstand and what they can do afterwards.
Tell the reader which feedback matters. Ask whether the example is understandable or whether the instructions are complete. A general request for thoughts may produce comments about colour while leaving the central problem untouched.
Use the response
Decide what changes, what needs another test and what lies outside the intended scope. Preserve the earlier version if comparing revisions would help.
Showing work does not require publishing every unfinished attempt. Choose a suitable audience and protect confidential material. The value comes from making an idea concrete enough to challenge. One honest prototype can reveal more than several persuasive descriptions of what the finished version might eventually become.