How to properly use a citrus juicer?

Could you please elaborate on the steps one should follow to properly use a citrus juicer? I'm interested in learning the most efficient and effective way to extract juice from citrus fruits, ensuring that the juicer remains in good working condition. Specifically, I'd like to know if there are any specific techniques or tips that could help maximize juice yield while minimizing waste. Additionally, is it necessary to prepare the citrus fruits in any particular way before juicing? Thank you in advance for your insights.