Be careful when attempting to trap feral cats, as they can cause painful injuries if not handled carefully.
If in doubt leave the trapping to the experts and ask your local cat shelters for help.
Consider what you will do with the trapped cat before you try to trap him/her,
as once a cat has been trapped it is difficult to trap him/her a second time.

Contact your local rescue centers to borrow a humane trap or buy one if you intend to trap cats on a regular basis. We bought our humane trap online from Trap Man.
To ensure the cage does not smell of other cats previously trapped in the cage, scrub the cage with a dilute bleach and hot water solution. Rinse well with hot water and allow to drip dry.
Shallow small lids or plates for baiting trap.
Tuna or sardines or mackerel for bait (plus tin opener fork, small plastic bag for rubbish
Catnip (Optional can be used instead of OR as well as food bait)
Blanket to throw over trap
Heavy duty gloves
String and Scissors
Book (Or other quiet entertainment to amuse yourself whilst waiting for the trap to be tripped)
Choose a location which is on solid ground and near a boundary, for example next to a wall or hedge. It is very important that the trap does not wobble or the cat will be reluctant to enter the trap. If the cats are being regularly fed place the trap as close to the normal feeding place as possible.
Try to ensure that the cats are not fed for several hours before trying to trap them. Place a shallow lid or plate with bait at the very back of the cage and dribble very small amounts of juice from the bait along the trap to the outside.It is usual to use a very smelly food to bait traps but cat nip can be used instead. Place newspaper or plastic cat mat on the floor of the trap, as many cats dislike walking directly on metal bars and lastly set the trap plate.
Do not leave a trap unsupervised, it could be stolen or removed by a well meaning member of the public. Also when cats are trapped they can panic, so it it better if you sit out of sight around a corner listening for the trap to be tripped.
When the trap has been tripped, quickly move to the trap to see which cat or cats have been caught is trapped, if it is the wrong cat release and try again. If it is the cat you want throw a blanket over the cage and allow the cat to settle for a minute before carrying the cage away. Keep the cat in the cage until you reach your final destination of vets, shelter, your spare room, as once released the cat will be harder to trap next time.
If there are several cats in the immediate area and you wish to trap a particular cat, the trap can be manned. Tie a length of string to the bottom of the trap door and after opening the door, do not set the trigger plate instead hold the string under tension to keep the trap door open. It helps if the string is threaded though the top of the cage to hold the tension. Stand as far back from the cage as possible holding the string taut and wait. When the cat you wish to trap enters the trap, let go of the string and the trap door will close.
If the cat is reluctant to enter the trap, tie the trap door open without setting the trigger plate. Ensure that all the cat's meals are placed in the trap. After a couple of days the cat should be happily entering the trap to eat, then set the trap as described above
If the cat you are trying to catch if particularly wary of humane traps or if you are trapping kittens the drop trap is a better solution. As kittens may not have the weight required to set off the humane trap.

Visit Alley Cats for expert advice and help in trapping strays and feral cats.