EPT
If you read tech which you should with this you should be leaning towards an obs build or stargate play in any regard. Scout with 1-2 phoenix or scout with chrono'd obs asap. After that it is tower management and base vision. Make your 3rd + pylons in a ring around your base so you can have vision of the drop +3-5 seconds faster. It ain't much but it helps. There are obvious "key" spots for the first 2-3 pylons on the perimeter as obviously you won't have full vision by the first drop.
After that it depends on comp but stalker/sentry is fine. Pull probes and DON'T RUN instead spread them out as best as possible. FF tight spots to block off the hellions and target down with stalkers.
