However, with rookies, you kinda need to be more in-your-face, like:

Include this file on all your PHP files, and make sure to style #fatalerror to fill all the screen so that the programmer needs to fix his code before something else.

Most errors inexperienced programmers come ask me help for are misnamed variables, so that helps a LOT. Initializing, checking array indexes before accessing them… those things happen a lot too.