At first, having a solid build order, or even an all-in, seems like a good idea - you beat 80% of the people you play, because they aren't prepared for an all-in, and may not even know what to do against one if they scout what you're doing and know what it means. You're soaring towards Gold, reach it, and hit a brick wall. Why is this?
Simply put - you can't adapt, and have bad habits. Your next step after scouting an initial build will be reacting to his reaction to YOUR altered build. However, this requires MORE scouting, and you'll have to gradually work it into your play, because it won't come naturally. It's much like keeping yourself from getting supply blocked - it's one more thing you have to keep remembering to do, constantly.
Some key scouting points:
- At 9 or 10 - initial build. Look for gas. Gas = tech. No gas = fast expand (FE) or rush
- At 30 - incoming push or tech direction
- At 50, scout the entire map for hidden expansions, especially if there's a lack of pressure. This is a good time for remote bases to be going up. If he's pouring money into an expansion, you can either crush it or gear up for a push against his main, but don't wait until he's recouping the cost of the expansion - hit him soon.
- Every 20 supply, up or down. If you gain 20, scout. If you lose 20, scout. You need to either capitalize on a gain or adjust to win the next encounter.
- After major battles. Win or lose, it might be time for a tech switch, either to surprise your opponent or react to his new tech.