How do I build a design portfolio when I have no client work?

You don't need clients — you need CASE STUDIES that prove how you think. Three strong ones beat twenty dribbble shots. Where they come from: 1. Redesigns of real products (the workhorse): pick an app with genuine problems, document the problems with evidence (reviews, your own usability notes), design fixes, explain each decision. The 'real product' grounding beats invented apps because the constraints are real. 2. Fictional-but-briefed projects: use design challenge briefs (there are sites full of them) so you're solving to a spec, not decorating in a vacuum. 3. Real problems near you: your college's awful course-registration flow, a local business with no site, a nonprofit. Even unpaid-and-unshipped, these are real users and real constraints — the most valuable kind. 4. One shipped thing, however small: a friend's landing page, a community's event poster system. 'Real and live' carries disproportionate weight. What makes each case study hire-worthy (this is the whole game): show the MESSY MIDDLE, not just the pretty final. Problem → who has it and how you know → options you considered → what you chose and WHY → what you'd do next. Reviewers hire the reasoning; the polished screens just prove you can execute it. What kills junior portfolios: walls of final screens with no context, 'redesigned Spotify because it looked fun' (no problem = no thinking shown), and inconsistency that reveals no visual system. One deeply-explained project outperforms ten decorative ones — every hiring designer will tell you the same.