In my experience, one of the easiest ways is to just get employed by a company, where coding is done in C. You will have to code in that language a lot and the

In my experience, one of the easiest ways is to just get employed by a company, where coding is done in C. You will have to code in that language a lot and the colleagues can help you. I also learned a few languages myself in my spare time (PHP, Python), but that is not nearly as effective. If you want to really be an expert on C (or in anything imho), you just have to do it fulltime.