If there's a DX oriented club in your state, join it. Participate in meetings and on-line discussions. If you're active on HF, get busy establishing your reputation as a competent DX operator, particularly with CW skills. If you're not active on HF, get a station going. Participate in every contest you can, submit your logs, and get yourself known by the DX community. Donate to other people's DXpiditions, support them behind the scenes as much as you can, continue to operate and become known to the DX stations as well as the DX clubs.
Then, maybe, they'll consider taking you along. Otherwise, roll your own, and make your reputation that way.