Distance

1. Make better contact

2. Swing faster

3. Use only Titleist equipment ;-)

You do this by:

1. Learning a correct swing for you

2. Repetition

You do this by:

1. Getting instruction

2. Range time.

John H is very correct with his advice but one other thing that could be added, try and make a larger shoulder turn, unless flexibility is hindered.

just one more thing to add on. keep swinging after contact. dont just go through the motion on the fallow through actully make it apart of your swing.