Eric’s Answer
Two big things.
The first is, if you are able, internships. They show that you have been able to succeed in a work-like environment already, which is a big plus.
The second is personal projects. If you have some interesting pieces of code you can show off (be they finished programs, libraries, or whatever), it will show that you have done more than just pass some classes. They can also be great jumping-off points during interviews. I had an interviewer notice that I had written a program in Racket, and they were interested in the language, so made a point of asking me about it. This let me show how I was knowledgeable, not just about the particular language but also that I could describe something I knew to someone who was unfamiliar with it.
Related to personal projects is helping out with Open Source projects. If you list that you are a contributor to some open source project, then prospective companies can check out the code you've written (if you give your username) to see that you're not just all talk, and it shows good involvement with the community. Open Source is a big topic, so you might already know this, but I'll put it here for anyone who happens to read it:
Open Source Software is software with source code that is freely available. There are many particular philosophies, but all are generally like this. As a result, it is possible for anyone who knows the language to submit changes to the software for the owners to consider, or even to make their own copies with the tweaks they want. Open Source software makes up a huge part of modern computing, from Firefox to Linux to Python, and even a lot recent software like Tensorflow. In addition, many closed-source systems, like Google Chrome and macOS, are built on top of open source projects (Chromium and FreeBSD, respectively). Most open source software has a community around it, so you can find where they are (often github.com, these days), and start to look around the code, look at bugs you might want to fix, and get to know the community to see if they have help for beginners.
All of these do take some additional time, unfortunately. But, I hope that there is enough flexibility in them to help!