A bag of lemons presents one problem for me. Faster than I can use them, they get hard and lose their ability to provide much (or any) juice! Since I hate to waste anything-wasted goods and foods are money lost to me-I take care of my lemons right away!
First, I get out my citrus juicer and juice all the lemons that I will not use in a couple of days. I am always careful to remove the seeds, Then I pour the juice into ice cube trays, place them in the freezer and let them freeze. When they are done, I put all the frozen lemon juice into a plastic bag. Using a black marker, I date the bag and place it in the freezer.
When I need lemon juice, I remove the amount I need from the bag. Each cube is close to one tablespoon. I usually let it melt. When I am making my morning drink, I just put the lemony ice cube into the cube and let it melt.
If you bake or cook with recipes that require lemon zest, make some before you juice the well-washed lemons. Dry it or freeze it!