this is a trick i learned. you can actually get an extra ounce or two from the same amount of grass. its very simple.
first juice up your grass like normal. then take the left over grass pulp that you would normally discard. add a cup or two of water to it. swish with your finger, allow the pulp to suck up the water. then put a tea strainer over an empty cup. slowly pour the pulp-water through the strainer into the cup. the water will be nice and green. now pick up the left over pulp in your hand, give it a really good hard squeeze. you will see lots of green water coming out. pour that water through the strainer into the cup.
repeat this at least one time. by the end of the process the pulp that started out dark green should be pale green. now add the water from the cup to your freshly squeezed juice.
all that green that you squeezed and leached out of the pulp is chlorophyll and minerals and vitamins!
this method allows you to get lots more juice from the same amount of grass.