This is a PvT tactic.

ASAP build a pylon. Build probes all the time, unless you can build the next building in the order. At about 9 build a gateway, then a CC at 11, and an assimilator ASAP after that. build a dragoon, then a Citadel of Adun (should be at about 13). Regularly make goons and probes until you have 1 probe at every mineral patch and 3 on gas (get the assimilator at about the same time as CC) and about 3-4 goons in reserve (about 19 supply, needs 3 pylons). Build a probe after that to scout for the enemy's base, then build a temp archives (when you have enough gas) and a second gateway after the archives have started warping. As soon as you have the temp archives built, have both gateways build a DT (as soon as you have enough funds). If you want, you can build a forge and upgrade them, or you could begin a second expansions nexus.
Either way, make sure the enemy is not waiting outside your base, then march your DTs and 4 goons towards their base. use the DTs to scout first before you move the goons in. try to knock out their comsat with the DTs, then move the DTs in while the goons pick off stragglers; if they have other detection, retreat b/c they probably have vultures or siege tanks defending their base (and goons lose on the lower ground). This attack will work on many Terran players because they won't expect it, but you have to be FAST. that is the most important part. They may decide to put in a missile turret or finish researching siege mode for their tanks (ouch) if you delay for even a minute, and the extra units you might have won't help you. Having a sair to look at their base layout before attacking may be helpful, but that makes your attack slightly weaker as far as ground power (building the gate and sair costs about the same as 2 goons or 2 DTs).