Note: there is no hard and fast rule on how to make a portfolio, but these are some general tips that can be applied
https://s3-us-west-2.amazonaws.com/secure.notion-static.com/e6eb9db4-d476-49db-8021-4c72300491e6/workshop.mp4
https://www.brandonxlaw.com/medium.html
This is a great case study that really goes into depth about his decision-making over even the smallest of details. You can see he did his research without explicitly referencing it.
His case studies are really long, but they read well. The reason they do is because he writes just what's needed to show what he did, how he did it, and the impact.
https://medium.com/startup-grind/i-got-rejected-by-apple-music-so-i-redesigned-it-b7e2e4dc64bf
Just a really creative project with solid rationale behind his decisions.
I really liked Roy's personal redesign projects specifically on the Honda Civic and Dominoes app. It's a great example of how you can do a personal project and make it shine.
https://essays.uxdesign.cc/case-study-factory
A great article talking about the "template" we discussed, and how to break away from it.