Heres a good little piece to help
Also, always protect your carbon workers. Maybe Build a Turret close to them and between your Command Centre, so if you do fall under attack, both your CC & Turret can cover each other.
Plus, build around 4-5 troopers, even at T1 to help protect your workers. Carbon workers are one of the first things that most attacking will head for. No carbon = no military.
Another tip is to build another carbon collection area a little distant away just incase.
Hope it helps