Develop your rhythm guitar skills. Strong rhythm skills are not only necessary for the rhythm guitar parts of the song; a strong rhythmic sense is vital for the guitar soloist as well. Good solos depend on timing and phrasing. Practice rhythm guitar parts as well as guitar solos with a metronome. Set the metronome at a slow speed, 50 beats per minute, and practice scale exercises and guitar riffs. Gradually increase the speed of the metronome to increase your speed on the guitar.
Alternate between rhythm and lead guitar as you play through a series of chord changes. Skillful guitarists are able to fluidly switch between rhythm and lead guitar parts because of their timing and rhythm skills. A simple way to practice this is to play a chord sequence, such as a 12 bar blues, switching from rhythm to lead. The 12 bar blues structure in the key of G is G/G/G/G/C/C/G/G/D7/C/G/G. The symbols "/ /" represents one measure or bar in 4/4 time. "/ /" gets four beats. Set the metronome at 50 bpm and practice playing chords in one bar and then guitar riffs in the second bar, chords in the third bar and so forth. Develop the ability to do this without losing your timing or your place in the progression.
Set up a rhythm and lead channel on the guitar amplifier. Set up a clean sound for the rhythm channel and an overdrive to heavily distorted sound for the lead channel depending on your taste. A slight overdrive sound may be all that is necessary to give the lead guitar enough boost. When the time comes for the guitar solo, step on the amplifier foot switch to change from the clean channel to the lead channel.
Control the rhythm and lead volume and tone with the knobs on the guitar. This is an alternative option to switching channels on the amplifier. Set the amplifier tone and volume controls for a strong lead guitar tone and volume. Turn the volume down on the guitar to the appropriate volume level for the rhythm guitar part. Adjust the tone controls on the guitar as well. Turn the volume control all way up for the lead guitar parts. Back the volume back down once the guitar solo is over.
Set up guitar pedals for rhythm and lead guitar parts. An overdrive pedal, such as an Ibanez Tube Screamer, can be used to generate a good lead tone. Set the amp for a clean rhythm guitar tone and step on the overdrive pedal to boost the sound for the guitar solo. Adjust the amount of overdrive or distortion to your personal tastes. Guitarists often used modulation effects (chorus, phase shifter and flanger) to get a rich and warm rhythm guitar tone.
Listen and study guitar players who are able to effortlessly able to switch back and forth between rhythm and lead guitar. Rock guitar players like Eric Clapton, Jimmy Page, Eddie Van Halen and Randy Rhoads are all excellent examples to follow. Pay attention recordings of their live performances. Jazz guitar players such as Joe Pass are able to integrate rhythm and lead guitar parts so well that you would swear there are two guitar players.