Terran Builds Against Defensive Players

So my previous build which was doing fairly well against [P] and [T] (didn't get to try against [Z]) Was I would build 2 barracks, one with a tech lab, one with a reactor, research Stimpak and Combat shield, produce marines and marauders, build a factory with a tech lab make four siege tanks, star-port with a reactor, make four medivacs them drop them on the opponents mineral line. This would destroy their main building before the army got there and usually wipe out the army, if I didn't they would be forced to attack which was thwarted by the military I produced during said attack. The game would end after that. But recently the Terran player would expand and be able to produce MT's throughout their base, or the Toss would have a scout following the drop and have their stalkers ready, rendering my tactic useless. So I would like to a good build to switch to counter-act this build. Also, when I see my opponent expand, if I haven't expanded, and only have been producing military, would it be a good idea to attack?

 

when your opponent expands before you, you have 3 choices:

1 - expand and harass him, force him to build more units
2 - harass him while you build up more units and do an all-in before he can get a good macro
3 - double expand <--- risky.

 

Attack, never go for 1 specific tactic or build. I double expand and make sure I'm at his base harrassing him, less risky..

 

Make him afraid of a large force... Even if you don't have one, you could force him to overproduce giving you an economic lead.