The phrase "throwing together" is a colloquial expression that often implies a haphazard or careless approach to something. Antonyms for this phrase would include words like "meticulous," "thoughtful," or "careful." These antonyms suggest a more deliberate and intentional approach to a task or project. Other antonyms might include "well-planned," "methodical," or "organized." These words suggest that the task or project has been carefully thought out and executed with precision and skill. Overall, antonyms for "throwing together" suggest a more careful and deliberate approach to accomplishing a task, rather than a careless or rushed one.