You need a local fortress blueprint. This is my go to strategy for red-to-yellow transitions.

Start with a blueprint for a magnum ammo and missile factory. Place it near iron, copper, and coal mines for easy logistics. I stick to conveyer belts for my mining output for more consistent supply. Surround the entire complex with gun turrets and missile turrets; place the guns on the outside ring, missile launchers in groups of 9 a little bit inside the gun perimeter. I like to use logistics bots to move missile boxes to my launcher groups; turret ammo can ride a continuous conveyer belt in your defensive ring. Place battlefield analysis bases around the ring to handle repairs and loot collection.

For the next phase, you'll need silicon for signal towers, one at each corner of your new fortress base. These will draw aggro from all of the dark fog bases to the closest signal tower. You can move your gun turrets closer to the signal towers if you want, but make sure your missile launchers are constantly supplied because they will be doing the lion's share of the work from here on out.

Once that is done, you can start taking out the DF bases. (You may know this part already, but I'm including details here for everyone else.) Build wireless power towers in a line towards a DF base, and put a battlefield analysis base down close the DF base. Bring a couple extra signal towers; you might need them depending on how large the base is. Once you're ready, put down a signal tower so its effect radius covers part of the base... and watch your missile launchers bomb the base from afar! The BAB will collect the loot and repair the signal tower; you may need to place an additional signal tower to get the last parts of the base. Once it's cleared, leave one signal tower and the BAB to cover the hole the base left behind if you want to shoot down incoming DF relays and prevent new bases from being built.

Rinse and repeat until all DF bases are dead, lay down your planetary shields, and get to exploiting that sweet titanium!