Re: Hints to debug
For the OP, knowing how to use the programs help. 
I’ve seen too many threads with people spending hours over issues trying to fix something when the setup is working how it should, just not the way they expected.
Being familiar with your server helps too. Anything borks, I (and others) will tell you to check your error logs first. They could be anywhere, it depends on your server.
I don’t expect people to be able to code, but for heavy debugging, you should be able to read the code and have a general knowledge of what it’s supposed to do. That comes with experience. You’ll also be able to check syntax that way, as a missing , : ; or } can do some pretty strange things.
Break stuff on purpose. 
Seeing what happens when you change one element you know you can switch back gives you +5 experience points. Use it wisely.
