Write an itinerary for the live performance, including the time allocated to tuning up and practice. Allow at least an hour to sound check.
Write a set list of the songs you will play. Make sure the songs are of a mixed tempo. Include loud and soft songs to avoid similar sounding songs being played consecutively.
Approach the soundman if the venue has one. Talk to him about the sound of the band and give him a reference CD of the band. Talk about any particular songs that may be different in the set and, therefore, require different volume levels.
Plug in the instruments and vocal microphones. The best durable vocal microphone used by bands is the SM58, but there are others are of good quality, such as the KMS105 and OM6. If operating without a sound man, make sure one of your band members acts in this role in his place.
Start with the low end frequency instruments such as the drums and bass guitar. Play the instruments individually and have the soundman or acting soundman find the appropriate level of sound.
Play the higher end frequency instruments, such as the guitars. Find the right sound level.
Test the volume of the vocal microphone. Find the right sound level.
Play all the instrumentation together and balance the sound levels accordingly. Push the vocals out in front of the rest of the instrumentation. The most common mistake of bands performing live is that the vocals are inaudible.
Play through a few songs to check the sound. Mark the levels on the mixing desk with tape and marker pen.