EPTTvZ - the most flavorful of matchups, I utilize a variety of strategies that pinpoint different zerg aspects such as the amount of anti air available to them in the early game or lack of units. The best way to maximize my success is to prevent zerg scouting. This is done by denying watch towers and scouting overlords that hover into your base. Unfortunately it is impossible to eliminate complete zerg map awareness. The creep spread alerts zerg players of where your units are on the map and overlords have ledges that can indicate army movement in advance (cloud kingdom, daybreak, entombed are 3 examples).
The second most important thing is what to scout. If I see the zerg try to take an economic advantage (such as slow gas), I can create a situation that best exploits the greediness through pressure or econ greediness of myself (except I am a little bit more greedy). By constantly reacting to scouting changes like a scan to tell if mutas or infestors, seeing how fast the gas and third base timings are, and amount of queens, zerglings, and roaches that are out on the field.
As the game peogresses, I try to utilize attacking from multiple tactical positions. Dropships are important to scout/deny additional bases, exploit zerg aemy being outpositioned or where no spores are, and to draw mutalisks away. Its like a dog fetching a bone. After they eats it, they come back to your base to harass you!
