How can I introduce two cats to each other effectively?

To introduce two cats effectively, start by keeping them in separate rooms and gradually swap their scents by exchanging bedding or toys. Then, allow them to see each other through a barrier like a baby gate before letting them interact face-to-face. Supervise their interactions closely and provide plenty of positive reinforcement and treats to create a positive association between them. Be patient and give them time to adjust to each other's presence.