Not for Myself
In Mahayana practice, my precepts and my practice are not for me: they are only for all beings. So I keep these precepts not for myself, but to help other beings. This means that sometimes, in some situations, breaking the precepts can help others much better than holding the precepts. If you mind is clear, then keeping the precepts is correct practice and breaking the precepts is also correct practice. The most important point is, why do you do it? Is it only for you, or for all beings?