Why Document?
Build documentation serves multiple purposes: a reference for future similar projects; a portfolio showing craft process (often more impressive to other cosplayers than finished costume shots); material for social media content (process posts consistently outperform finished costume posts in engagement); and a record of what you did, so you remember what worked and what to do differently next time.
What to Photograph
Capture: the raw materials before cutting; each significant construction stage; any innovative technique or solution to a specific problem; before/after shots of each major element; the first full fitting. These don't need to be artistically composed — useful documentation prioritises clarity and showing what was done over beautiful framing.
Basic Photography for Build Documentation
Good light is more important than a good camera. A window with natural light, positioned to illuminate the subject, produces better build documentation photos than a phone camera in a dark studio with a phone flash. A consistent background (a piece of white foam board or a plain light-coloured wall) makes the subject the focus.