Crosslinking sites?

So basically I'm building up my portfolio site, just for when the occasional web dev clients come in.

To every site I've built my link into the footer. I want to provide the sites as examples on my site though, to show off my previous work.

Is this not a good idea? What would you recommend me to do instead in that case?

I had the same question:
https://www.blackhatworld.com/seo/websites-cross-linking-good-or-bad-for-seo.1272305/

There's nothing wrong with that. Large media companies do it all the time. Look at Dotdash.

The term “crosslinking” is used in several ways when referring to websites. Most commonly, crosslinking refers to the process of linking between two separate websites. But crosslinking also applies when associating two pages on the same website, so that each page shows a link to the other page.