The adductor machine is a great exercise to work the muscles of your inner thigh. It may be useful to warm up your muscles with a light weight prior to your training weight, as this will not only help prevent injury, but also make sure that the machine is set-up comfortably for you.
Sit with your back pressed into the adductor machine, holding on to any handles and with your legs and feet pressed against the foam pads.
Smoothly bring your legs together, focusing on using the muscles of your inner thighs - your adductors, hold for a second, then return under control to the starting position.
Some adductor machines will have a combination of settings, allowing the legs to be taken wider. Avoid taking your legs out too far, especially for beginners, as this can cause you to strain your adductor muscles.
Aim to keep your legs and back in contact with the machine at all times.
As you lower the weights, always avoid letting the weights heat each other, aim to keep the contraction within your adductor muscles by not allowing the weight your lifting rest on the machine as your performing the exercise.