Watch the Fills online guitar lesson by Jeff McErlain from Blues Survival Guide: Rhythm Edition
In music and comedy timing is everything. Where we place a fill is extremely important, if it is off it can fall flat and really mess up a tune. A great thing to practice is playing rhythm guitar for a bar then fill for a bar, repeat. We can then play rhythm guitar for two bars and fill for two bars then repeat. I highly suggest you use a metronome on this because it will keep your time honest! It will also build up your internal sense of time.