The sound check process is the one of the important parts of your stage work. The purpose of the sound check is ensuring the right sounds get to the sound booth, to the monitors, and to the house speakers.
Things to follow
Step 1: Line check to verify signals being sent to mixer
Step 2: Play so your volume can be set
Step 3: Set those monitors
Step 4: Play so the sound tech can mix.
To read more about this follow this link from Chris Huff
Sound is everything in Music.