Hi!
I’m at a similar level as you are. I just graduated and am currently working on my portfolio. You have some great suggestions for setting up a portfolio here, but I have a couple of suggestions to add about how to come up with new projects to add to the portfolio.
To decide what kinds of tools you should use for creating projects, you can take a look at the job descriptions of the types of jobs you are targeting. If they list specific tools like ArcGIS Online, or ArcGIS Pro, it makes sense to use those tools in your projects. You don’t have to cover every tool listed, but it’s a good idea to get really comfortable with at least one or two of them. You can also look at the descriptions to see what kinds of products they are looking for such as analyses, web maps, automations etc.
One strategy you can use to choose the topics of the projects you are working on is to focus on projects in the domain that you are targeting. If you are looking for environmental jobs, you can work on projects such as mapping the consequences of a drought or changes in land cover over time. If you’re targeting infrastructure jobs, maybe a map of rail lines or major roads will work better.
Additionally, you can show some personality by making projects related to your personal interests. For example, I am currently working on a web mapping application about owl sightings, and my previous project was a gardening website, because those are things that I am interested in.