These are not noob mistakes but things that noobs have a hard time finding out, it took me like two years!
- You can boost your build range when assisting other units. So if for example your acu is building something, you can select nearby engineers and right click on the acu and you'll find that some of the engineers that should be out of range to immediately assist actually can. This can be a major time save especially in groups and buildings or factories can be assisted to completion much quicker. I do this constantly, every game.
- This bug/feature of attack deployment from the factory is a major boost to your economy and gives you a fast start on pretty much every map. Absolutely essential to use.