Synonyms: careful, conscientious, thorough, painstaking
careful: showing attention to details
Example: We are always very careful to give accurate information. The project
needs very careful planning.
conscientious: working carefully and well
Example: She’s a very conscientious worker.
thorough: including everything that needs to be dealt with very carefully
Example: The police have carried out a thorough search of the woods.
painstaking: done slowly and carefully in order to avoid mistakes
Example: The design is the result of years of painstaking effort.
without any care or thought