Conditioner bars are ideal if you're trying to eliminate unneeded plastics from your life. They have far less packaging, if any because they're all bar and no bottle. They also work great and last way longer than your regular bottled conditioner and are so convenient when traveling thanks to the tin that comes with them.
Simply rub the bar directly onto your hair, paying specific attention to the ends, comb your hair, leave it on for a minute, and then rinse. You can also reapply a small amount after rinsing and keep it on. It is essential to keep it dry in between applications.