You can use two methods . A whistle or an electronic predator call.
The whistle , just Google " Tenterfield Fox whistle " is used to mimic a rabbit in distress . It works best under a spot light at night but still can be used during the day if you are well hidden , and don't move too much.
This vid gives you some idea although the whistle used in the vid is not the best sound.
[ame=http://www.youtube.com/watch?v=MUhK0yVAENU]Fox hunting/whistling/shooting - YouTube[/ame]
