Leaky faucet - How can I repair it myself?

Before you take anything apart, check underneath the sink - there's usually a shutoff valve down there that lets you just turn off the water without shutting down the whole apartment. Makes things way less stressful. 😊 The previous tip about the washer or cartridge is right, but honestly with a lot of older faucets the problem is just limescale - often you can just unscrew the aerator (that's the screen at the spout), rinse it out and flush it through. Costs nothing, takes two minutes and saves you half the repair work.