In order to organize a successful offseason event, the first step you should take is create a committee full of committed and dedicated members. Choose a team leader in the committee who would be able to oversee everything and delegate jobs to other members. At the same time, you have to get teams, parents and mentors involved. Chris Fultz uploaded a very useful whitepaper here regarding how to organize an offseason event. This is a very detailed document and I suggest to read through it. It can be found
here. Good luck and I hope to see an offseason in Texas very soon. If I can be any help, please don't hesitate to contact me.