Not rly.
Always keep an observer at ur entrance and ur resource nodes.
(Overlords need upgrades these days to be one)
Use ur HQ-powers. Queens for extra larvae, Chrono-boosts for faster production of units (probes and zealots at start), Radar thingy for terrans for extra income (dont upgrade ur supply depots.... mules ftw).
With all the reapers, blinkers and tunnelers.... defend all ur base not just the bottleneck
And use the replay, build order breakdown a lot.
Watch why and how u lost. Thats the best way to learn i guess.