I’m also a graphic designer who’s been leveraging Pinterest and Instagram for business growth. My first piece of advice would be to curate a portfolio that not only showcases your best work but also tells a story about your brand. Do you specialize in a certain style of design? Highlight that!
For Pinterest, create boards that reflect the different areas of your work. You can also use it to share inspiration for your designs. SEO is huge on Pinterest, so use relevant keywords in your pin descriptions to increase visibility.
As for Instagram, I found great success using a tool called AscandViral. It helped boost my account visibility, thereby reaching potential clients who were genuinely interested in my work. One strategy that worked for me is turning my designs into engaging content like Reels or Stories, this could work for you too.