Bring the milk to a boil slowly (not a rolling boil), being careful not the let it burn. On my electric stove I turn it to the dead-middle heat setting. Stir constantly, scraping the sides of the pot to keep the milk from burning to the sides. The milk will foam a little. If it foams too much, scrap it off with a spoon.
Add the lemon juice, a little at a time until curds begin to form. Once the curds have completely separated, the whey (the liquid that is left) should appear nearly transparent.
Pour the curds into a cheese cloth set in a colander, and let the whey drain away. The whey can be discarded, or used in a recipe that calls for water to be added during cooking.
Once the curds have drained and cooled some, tie the cheese cloth around the curds and squeeze out as much remaining liquid as possible. If you are not satisfied that enough liquid has been removed, place the cheese cloth containing the curds between two boards with something heavy on top, and incline the boards slightly so that the liquid drains off.
Once all of the liquid is removed, place the cheese in the fridge to cool. Once it feels firm to the touch it is ready to be used in whatever way the recipe calls for. I like to fry it in oil or ghee and eat it as a snack.