If you want to get the most juice out of a lemon - short of using a dedicated citrus juicer (like semi-professional lemon juicer Adam Pash does), break down the lemon by putting some pressure on it before cutting.
Photo by Bobbi Bowers.
Jennifer Semon Rostal writes:
Before cutting them, put them on your counter and roll them back and forth, applying heavy pressure with the heel of your hand. This will help break down the lemon and make them easier to juice! Use a tool like a citrus reamer to get out more juice than you could squeezing with your bare hands.
My fellow Lifehacker writer, Alan Henry, vouches for this method too. Seems like everyone has their favourite way of juicing lemons or tips for using lemons. What's yours?
Tips and Tricks - Lemons [A Self-Confessed Foodie]