- Leave base immediately and start searching for the instant pickup that grants you 100 gas. Once you find one return to the main ship and build a scanner tower. Drop 1 turret down by the tower and being mining the crystals in the spawn area. While you mine, start scanning. Use the main ships battery to keep the scanner tower charged.
There are two things you need to find with your scanner
- Rich mineral fields. Mine out the first and closest one you come across, you will have time to scan for more later.
- A factory, and to a slightly lesser extent a science vessel. I always build two mules, sometimes more. I usually don't make science vessel units, but the structures it unlocks are valuable.
- In team games it's good to grant control of your units to your team-mates. This will let them use your scanner towers, restoration buildings, and command units to repair etc. Do this if you're playing with people you know.
- You can clear most zerg areas with a restoration building and a scanner tower faster and cheaper than you can with turrets and tanks. Simply scan for the creep tumors and snipe them with your SCV, use the restorer to restore your energy for more sniping. Once the creep is gone, the zerg buildings will die off. Hatcheries and extractors don't need the creep to survive, so you will need regular firepower for those.
- Mules can be set to autorepair. They are pretty cheap and you'll want 1 or 2 at each front of your base just for the repair.
- Bunkers are an enhanced barricade, I was overlooking these in my first few games. They can also be upgraded with a turret.
- Eventually you will want to move to a hilltop to build your base, one with only two ramps. The waves become extremely tough. If your base is being attacked from all sides it is not going to survive later waves.
- The zerg disruptor and mind control structures are both very valuable, don't overlook them.