From a former GC superintendent and project engineer's perspective: Communicate with your GC and the other trades. Communicate, communicate, communicate. Do not make assumptions about what the other subs are doing, or about things that are vague on the plans or cannot be built as drawn. Do not let others make assumptions about what you're doing either - just tell them all how you're going to handle the job (sequence, materials, methods, and schedule) and keep everyone updated as the project moves along. If the plans don't work as drawn, come up with your preferred solution to the problem and run it up the chain of command for approval. Don't just do it your way without communicating first, and don't just complain about problems without proposing solutions. You're in project management now; solutions are your job. Remember that as the superintendent for a major sub, the GC is expecting you to be a big-picture person who coordinates the integration of your trade's scope with the rest of the subs on the jobsite - smoothly, efficiently, and without drama.