Install new strings, and set the action (height of the strings) and intonation (pitch adjustments made at the bridge) as accurately as possible. New strings will set your guitar up for its best performance.
Tighten all screws, nuts and fittings on the body of your guitar. This will eliminate any rattling or squeaking sounds that can make their way into your amplifier and speakers.
Tune your guitar as accurately as possible. Use a high-quality tuner. Stretch your strings by lifting them 1 or 2 inches from the fretboard at the 12th fret. repeat this process several times until your strings return to the correct pitch after stretching. This will help your guitar stay in tune accurately while playing for extended periods of time.
Route your effects. Effects pedals and processors are extremely popular with electric guitar players. Chorus, reverb, distortion and echo effects add color and excitement to your sound. Use shielded cables for all your connections.
Place distortion and compression-type effects first in your chain, followed by modulation and time-based effects like chorus and delay. If your amplifier has an effects loop, try connecting your time-based effects between the send and return jacks. This will result in a more pleasing tone when using these effects, as an effects loop places them late in the signal chain, after the preamp section of your amplifier.
Adjust the parameters of your effects. Start with low to medium settings on the intensity and mix controls of your effects. Setting these values too high can overpower the tone of your guitar signal, and result in a thin or "processed" sound.
Set all the equalization controls of your amplifier to their zero or neutral positions. There are thousands of amplifiers on the market, but common to almost all of them are bass, middle, high and gain controls.
Play your guitar and make small adjustments to the equalization controls to taste. You may wish to reduce the middle control for a more modern rock tone, but remember that the guitar operates in the middle range of human hearing, so removing too much mids can make your guitar sound thin or harsh when playing along with other instruments.
Adjust the gain control. Gain refers to the amount of distortion added to your signal. Although many styles of rock and metal incorporate a lot of distortion, try to keep the gain control as low as you are comfortable with regardless of style. This will preserve clarity in your tone.