I have had great success with this:
Put the trap out and use a zip tie to tie open the trap door so the cat can go in and out without being trapped. They are curious - they will check it out and become comfortable with it if it poses no danger and does nothing to startle them.
After a short time start putting food outside of the trap and inside of the trap. After a few days of this put the food only inside of the trap - still leaving it tied open with the zip tie.
After a few days when the cat is going into the trap to eat - simply cut the zip tie and set the trap with the food in it. This has worked very well for me in the past and I am in the process of doing it again!
Perhaps you can try to use more than one trap as well. When I am doing this often I will find cats laying inside of the trap sleeping because they have become so comfortable with it being around.
However, I do have a couple of girls that are very stubborn that I've been unable to catch - these are the ones I am out for this time. So, good luck to us both!
Any suggestions on how to catch a 5 pound maniac of a feral cat? Animal Control left a trap but this thing has more than 9 lives and keeps getting out.