Here's a few tips using lemons or limes, if you just need a small amount of lemon or lime juice but don't want to waste the whole thing, instead of slicing it in half just puncture it and squeeze the juice out. Store in the fridge wrapped in plastic!
When you are juicing the whole fruit, roll it back and forth on the counter with the palm of your hand to release the juice from the segments inside.
Save the rinds in a plastic bag in the freezer so the next time you need lemon or lime zest and you don't have any fresh, just grab the rinds from the freezer.
Use any leftover citrus rinds to keep your disposal fresh, just grind them while you have the cold water running, smells wonderful!!