Question Authority - No idea is true just because someone says so, including me.  Think for Yourself
 Question Yourself - Don't believe anything just because you want to. Believing something doesn't make it so. Test ideas by the evidence gained by observation and experiment. If a favorite idea fails a well designed test, it's wrong. Get over it. Follow the evidence wherever it leads.
 If you have no evidence, reserve judgment.
...and perhaps the most important rule of all: Remember, you could be wrong - Even the best scientists have been wrong about some things. Newton. Einstein. And every other great scientist in history. They all made mistakes. Of course they did, they …