The best trap has openings at both ends, so that before it's sprung it looks like a wire tunnel. Rabbits are less reluctant to enter if it looks like it's got more than one way out. Some skill is required in setting the control on the trap so that it springs at a fairly light touch from the rabbit's foot. Practice using the controls at home until you get a sense of how they work. You can, in effect, make the trip-plate bigger by setting a piece of cardboard on top of it, and putting the bait on that.
Bananas are a good first choice.
Next would be grated carrot, as grating tends to release a stronger smell. Drape a sheet over the whole trap. This will make it less scary to enter and less stressful for the bunny once he's inside. Place the trap in a shady, somewhat secluded spot, for the same reasons. You must check the trap at least every 4-6 hours.