I highly recommend purchasing an electronic tuner (especially one that includes a metronome).  You should use your tuner as a training tool to improve your tuning skills.

How often should you tune your guitar?  Every time you pick it up!

Be sure to memorize the note names for each open string on the guitar.  From the six string it goes like this: E A D G B E.  Maybe this will help, “Eat At Denny’s Get Big Eggs.”

Try the six-step tuning method that is given in this lesson and then check your tuning with your electronic tuner.  How did you do?