Adjust the attack setting. The attack setting controls how quickly the compressor/limiter will act on the incoming audio. Set a fast attack time (0 to 20 milliseconds) for vocals and guitars, and a slower attack (20 milliseconds and up) for drums. This will allow some "punch" to get through.
Adjust the release setting. Typically, a medium release time (20 to 100 milliseconds) will yield the best results . A faster release setting can work well with vocals, but if the release is too fast, the effect may begin to sound fake, and sit badly in the mix.
Adjust the ratio. The higher the ratio setting, the wider a range of dynamics will be applied to your audio signal. A good place to start is a ratio of 4:1. Use a higher ratio for more dynamic signals like vocals and drums, and a lower ratio for signals that are more constant in volume, such as a bass guitar or keyboard.
Set the threshold level. The threshold setting determines at what input volume the compressor begins to act on the audio signal.Adjust this setting last, so that you can see the effect of the other settings. Watch the reduction meter; adjust the threshold until the compressor/limiter is reducing the volume by the amount you wish.
Set the output. After adjusting the other compression/limiter settings, you will notice that the overall volume of the signal has dropped. Use the output setting and its corresponding meter to adjust the final output level to be as high as possible without creating distortion.