Walnut Creek, California
Because of my experience in long driving I get a lot of players coming to me for lessons on how to increase their distance, both off the tee and otherwise. There are a lot of things that you can do to hit it farther.
Many of my tips include a reference to keeping your hands relaxed rather than tight. This is much easier to do if the grips on your clubs are in good condition.
It is easy to overlook the importance of this aspect of your equipment. Many golfers that want more distance have old, worn out, slippery grips on their clubs -- which almost guarantees that their hands will be too tight. Make sure your grips are either new, clean, tacky or textured in some way. If they're made of rubber and aren't very old you can usually rejuvenate them with warm water and dish soap, abrasive cleanser, or even sand paper.
Having grips that are in good condition will go a long way toward having a relaxed grip and hitting it farther.