Certainly reading a lot of good C code is a part of this; for me, reading the predecessor <i>Lions&#x27; Commentary on UNIX 6th Edition, with Source Code</i> (<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Lions%27_Commentary_on_UNIX_6th_Edition,_with_Source_Code" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Lions%27_Commentary_on_UNIX_6t...</a>) was a key part of my learning serious C in the early &#x27;90s.<p>Plus of course hacking on programs, most often various ersatz Emacs versions that would run on a PDP-11.  I.e. something I <i>really</i> wanted to get working to my satisfaction.