In a large mixing bowl, whisk together the flour, salt, and sugar until well combined.
Add the cold butter cubes into the flour mixture. Using a pastry cutter or your fingertips, quickly blend until the mixture resembles coarse crumbs with some larger butter chunks remaining.
In a small bowl, mix the cold water and lemon juice. Gradually pour this into the flour mixture, stirring gently with a wooden spoon until the dough starts to come together.
Turn the dough onto a lightly floured surface and form it into a rough rectangle. Be careful not to overwork the dough.
Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.
After chilling, remove the dough and place it on the floured surface. Roll it out into a rectangle, about 1/4 inch thick.
Fold the dough into thirds, like a letter. Rotate it 90 degrees, roll it out again, and fold it once more. Repeat this rolling and folding process two more times for a total of four folds.
After the last fold, wrap the dough in plastic wrap and refrigerate for an additional 30 minutes.
Your puff pastry is now ready to be rolled out and shaped as needed for your favorite recipes.