Clients do not study portfolios. They scan them for evidence that you have already done the thing they need. Build for that behaviour.
Lead with the work you want more of
Your first three pieces determine what you get hired for. If the top of your portfolio is wedding video, you will be offered wedding video. Put the work you want to repeat first, even if it is not the most recent.
Fewer, better
Six strong pieces beat twenty mixed ones, because the weakest item sets the perceived standard. Remove anything you would not want to be judged on, including old work you have outgrown.
Give each piece context
For every item, add two or three lines: what the client needed, what your specific contribution was, and any constraint you worked within. On collaborative work, say exactly what you did. Clients cannot tell from the finished piece whether you shot it, edited it or mixed it.
Make it easy to consume
Short excerpts for long pieces, with a link to the full version. Audio should play instantly. Video should not require a download. Everything should work on a phone, because that is where most people will look.
Complete your profile
A portfolio sits inside a profile, and the profile answers the practical questions: what you do, where you are based, whether you work remotely, your specialisms, your availability, a rate range if you are willing, and how to contact you. Missing location and contact details cost more work than a weak portfolio.
Keep it current
Update after each significant project while you still have the assets and permission. Set a reminder every quarter. A portfolio whose newest piece is three years old suggests you are not working.
Permission and credit
Confirm you are allowed to show client work, particularly anything internal or unreleased. Credit collaborators. This costs nothing and is noticed by everyone in the industry.
Test it on a stranger
Ask someone outside your field to look for thirty seconds and tell you what you do and who you do it for. If they cannot answer, the problem is the structure, not the work.