I use GDB for C code, if only to get the nice backtraces, but other than that I find its easier to just think things through and put a few debug statements in.

I use GDB for C code, if only to get the nice backtraces, but other than that I find its easier to just think things through and put a few debug statements in. Setting a DEBUG constant is usually pretty handy - I surround any debug output with an 'if (DEBUG){}' - it makes it easy to turn on/off the extra verboseness.