There are many things you can do to get a clean recording with minimal spill between microphones. Try recording in the quietest place possible, ideally in a room with minimal reflective surfaces (such as floorboards). Place the microphones as far away from each other as possible, faced away from one another. Positioning each microphone less than six inches from you and your guests’ will also help to capture a clean signal (you may need to use a desk stand or studio arm like the RØDE DS1 or PSA1+ to achieve this).