The term 'un-methodical' suggests a lack of orderly planning or systematic approach, and antonyms for this word may include terms such as 'methodical', 'organized' or 'systematic'. These words all suggest structure and a clear approach to tasks or projects. Some additional antonyms could be 'precise', 'meticulous' or 'disciplined', which all suggest a focus on detail and accuracy. Other possible antonyms could be 'coordinated', 'planned' or 'deliberate', which suggest a level of intention and purposefulness in one's actions. Ultimately, choosing the appropriate antonym for 'un-methodical' depends on the context and intended meaning of the text.