The phrase "doeth to a t" means performing an action with precision and accuracy. Some synonyms for this phrase include "executes flawlessly," "accomplishes perfectly," "performs with exactness," and "fulfills with precision." These words all convey the idea of carrying out a task with meticulous attention to detail and completing it with excellence. Other words that can be used as synonyms for "doeth to a t" include "implements faultlessly," "executes faultlessly," and "carries out flawlessly." By using these words, a writer can convey the message that a task has been completed accurately and to the best of one's ability.