First of all, you can recommend each other. When a couple goes to one of them to customize their own wedding service, they will be recommended to the cooperative place, give appropriate discounts and get a small commission from it.
Then, you can also choose supporting services. This requires the two companies to make concessions on mutual interests, taking their own interests as the main body, and the other supporting business is the subscription package chosen by the newcomers.
In short, cooperation should take into account both possible benefits and lost benefits, so as to make full preparations and deal with possible problems in the later stage.