1. Use Private Repositories
When using hosted version control (like GitHub), often when a repository is created the default is open to the world. Although this is great for Open Source projects, it is not good at all for coursework or private projects! Make sure your repository is set to private so others can’t use your work. The GitHub Student Pack comes with unlimited private repositories (and a lot of other free stuff!).
You can learn more about how to use Git here.
2. Checksum your downloads
When downloading files from the internet or other remote locations, a file can be modified in transit or swapped out on a file hosting mirror to contain a malicious payload. A quick check to confirm the integrity of a download is to perform a checksum, usually on the command line like so:
The output can then be checked against the checksum provided usually underneath the download link you have used.
Learn more about how checksums work.
3. Use a VPN
A virtual private network encrypts the traffic from your computer to a known (and hopefully secure) endpoint. This can be great for accessing University files or services from off-campus but also can prevent traffic-sniffing on public WiFi networks, like coffee shops.
The University VPN is a great place to start.
4. Secure Personal Websites
An SSL certificate for your personal websites/projects is not only a great way to secure traffic between user and server but it is also free through the LetsEncrypt project. There are some great guides on how to secure your site within a couple of minutes, like this one for CentOS.
5. Vary your passwords
Using the same password for all of the services you access is not a good idea (you probably already know this). Use key-based access where possible and consider using a service to manage your passwords (like KeePass).