Partnering with Businesses or groups?

Have any of you tried partnering with any businesses or groups to get clients? I have been thinking about trying to partner with some other local businesses and groups to help grow our photography business. I know we want to make sure that we can be available to wedding venues and other businesses that our potential clients would be likely to use. I am struggling though with what we can do to make sure that we are adding value to their business as they are referring us. Any ideas on types of business I could contact and possible ways we could benefit them? Thanks!