I'm a CS student in the UK, in the summer before my final year. This summer, I want to start putting together a portfolio of personal projects that I can later present to employers when I'm job hunting.

I'm unsure where to start as I want to avoid sinking my time into personal work which is unlikely be of much benefit.

I believe part of my problem is a lack of clear direction; I want to work as a software developer, but beyond that I'm non-specific. Should I research to get a clearer idea as to exactly what kind of software I want to work on, technologies I want to work with, etc.? Or, is it normal to be more open, and to mold oneself to whatever job you find/can get?

My other problem is that while a lot of the advice out there is "just pick something you want to make and learn programming by doing it", does this approach have any downsides? For example, getting too acquainted with one programming language/paradigm without sufficient exposure to other ways of doing things, or perhaps none of the projects you chose to work on required you to work with databases, or you didn't learn version control, etc.

What I'm asking is, are there any pitfalls to the "just learn by making stuff" approach? I want to make sure that I'm building a rounded skillset, as opposed to being good at one aspect of software development while being completely ignorant of other skills/knowledge that the job/employers will expect.

Thank you if you've read this far. I'm really quite unknowledgeable about this kind of thing, so I hope you can be kind to me. I'm just trying to prepare myself as best as I can so that I can become a useful, skilled individual with a good shot finding good work.