<p>It is not recommended to ask a teacher you've known only the 12th grade for a recommendation, even if you're a standout student?</p>
<p>It depends. You want the teachers who will write you the strongest recommendations. They tend to have known you for longer periods of time, but they don’t have to. Most people will probably have teachers from junior year who will write stronger recommendations than teachers from senior year will, but other students would rather ask senior year teachers.</p>