A design portfolio is one of the most important things a designer needs as it showcases the quality and breadth of their work. Not to mention that your portfolio determines if potential clients will hire you or not.
That being said, make sure to curate your images in the most compelling way devoid of any mistakes. Here is how;

Relevancy: Take the time to look at all of your work and carefully choose projects within a specific design field that you might be interested in or want to be hired for. Remember to choose the best!
Presentation Is Key: Consider using only high-quality, high resolution images that present your work in the best light.
Context: Describe your work in a unique way. Make sure to highlight the scope of your work, your client, and your process. Prospective clients should be able to get a sense of what you created almost immediately.
Updates: Make additions to showcase your new and better creations as you create new and better work.
The best way to ensure you give your work the credit and attention it deserves in your portfolio is to build in time at the end your creative projects for planning and prepping your pieces. It's essential that you update it regularly with your best recent work and, above all, view it as part of the creation process.