Whether you play basketball, volleyball or any other sport that ever requires
you to jump you simply need to jump higher.  The good news is that you can
learn how to jump higher fairly quickly.  It's not impossible to gain about
an inch in vert each week for a couple of months with the right training. 
I emphasize that you have to know what your doing or you could be wasting a lot
of time and energy. 
Why should you train like a beach volleyball player?  Can you think of
anything harder than jumping out of the sand?  My point exactly. 
These athletes have jumping down and their jump training is the best on the
planet.  How do I know?  Because I have played with the pros and know
what is required to jump high in sand. 
Nobody can naturally jump high in sand, it takes a lot of workouts to be able to
get out of deep sand.  Plyometrics are essential in the workout routine of
any beach volleyball player. What are plyometrics?  They are exercises
designed to produce both muscle strength and speed to produce power.  You
can't have power without the combination of both. 
You get the strength by doing workouts with weights much like you would see a
bodybuilder doing but you focus more on speed of movement than amount of weight
lifted. You get the speed by doing things such as box jumps.  Jumping
onto or off of a box will train your golgi tendon reflex to react with more
force which will cause you to jump higher.

Learn How To Jump Higher: http://jumpmanu.hot.to/