The antonyms for the phrase "turning to advantage" are numerous. One possible antonym is "wasting opportunities." Another possible antonym is "neglecting." Some other antonyms for "turning to advantage" are "ignoring," "misspending," "mismanaging," "squandering," "frittering away," "misusing," "allowing opportunities to slip by," "blowing chances," and "losing benefits." All of these antonyms describe the opposite of using situations or circumstances to one's advantage. To avoid such negative outcomes, one must be cognizant of opportunities and make conscious efforts to capitalize on them. Thus, it's better to cultivate a sense of mindfulness and alertness for the chances that can be taken advantage of.