warm up some water and let lemons/limes soak in water for about a minute. then roll lemons/limes with pressure on a hard surface until they are a little squishy.
now cut you lemon/limes in half and stab the fruit (NOT the skin) a little to make it easier to squeeze out the juice. squeeze your lemon/limes into a mason jar with measurements until you have 1/2 a cup of juice.
(start here if you're using presqueezed juice)
take your 1/2 a cup of juice and microwave for about 30 seconds. take the warm juice and pour 1/2 a cup of sugar in. stir until the sugar completely dissolves.
add 3 1/2 cup of filtered water to your juice and sugar. mix thoroughly, and filter out the pulp and seeds with a coffe filter.