Espresso is basically served with lemon rind at some restaurants. Lemon rinds are quite useful if you don't like bitterness in the taste of your coffee. Just put the lemon rind at the top of your cup for a few seconds and it will soak up the entire bitterness from your cup. But we all know that some amount of bitterness is the essence of espresso. This tip is only for those who are entirely against bitterness.