Track down a syntax-aware code search/database tool (if your IDE doesn't have one). For me it was/is GNU ID Utils. At some point you'll be handed thousands or millions of lines of someone else's code, and you will need to find things quickly and completely.

Also, turn on all compiler warning flags all the time. Some compiler warnings aren't triggered unless optimization is enabled, so turn that on every now and then during development and see if any warnings pop. If you're handed thousands of lines of someone else's code and it's riddled with warnings, fix them first.