What are some common mistakes to avoid in Supreme Commander?

[The General]

If you're giving gaming advices to those who are still newbies to playing Supreme Commander, what are the errors which you're going to make them aware to avoid committing in the game? Will you focus more on poor resource management, overextending their forces, or neglecting defenses when advising them?

 

[Blitz]

I'd advise to avoid poor resource management and also make sure to balance your economy. Additionally, don't over-spend on units as well. These are essential points to consider.

 

[Vortex]

Have a look at this: