As James Bach says "Best Practices was a term made up by marketers". Watch interviews. Learn how to ask the questions that will help you find bugs. Also, it's not necessarily about practices that you employ, but rather about the tools you use and create to help you find bugs more efficiently that make you a better tester.
Also, to keep up on your skills start testing some open source projects. It's something you can add to your experience list to show that even though you haven't had an 'official' job doing something; you have been keeping up your skills as a tester.
As far as courses go, go get some books. Beautiful Testing by Adam Goucher and Tim Reilly is a great composite of professional tester experiences. Also good is the Art of Software Testing. It contains some exercises to help you understand where you're at and some great reading for improving your thought process.