Networking
These days, networking is my bread and butter. So, I apply what I've learned on the job at hom for my benefit.
VPNs are great for various reasons, until you ask Reddit, then they're the worst ever. I solved my lack of publicly reachable IP using a VPN. Bonus nachos: I get ad blocking on the go now.
Yes, first server is great, but what about second server? Meshing VPNs for more resilient home access. Sort of. Mostly for the academics.
Rolling your own VPN is great, but limited (Unless you're filthy rich). Commercial has its place.
Sometimes the old ways are better. This isn't one of those times, but it's still useful.