As the Driel race and you are automatically inside a fortress, like in the secnd or third campaign mission, the first thing you should do is raise the Mound to status level 3. When you do that, make a Wormery and make three or four Dex Worms. Put each of them at an entrance to the fortress. Then, make all kinds of soldiers. There are several combinations you can make. Either start by making soldiers or by upgrading the mound. If you upgrade the mound first, research the fencing after making the Dex Worms and soldiers. When you complete the research, build walls all around the supplies so that enemies cannot get in unless they break. Note: During all of this, you must get supplies with your drones.
While in the human/colonist race, the first thing you should do is upgrade your Control Hub to level 2. Next, collect a lot of supplies and make the Gunner Training building. Once done, make about ten Gunners. After that, make the Probe Station maker thing and make the Scouting Probe that you learned about in the first mission. Put your Gunners and the Scouting Probe as Team/Group 1. Put the Scouting Probe in the front of the triangle formation, then follow the roads destroying buildings and enemies as you go. Always have an extra probe at the main base since the probe is weak in defense and gets killed easily. With this combination you will win almost every time. Note: Always have a main base defense of about five or six Gunners.