First, and foremost, spend time with them.
Include them in your life, talk to them, and share the things that happen with
them… treat them as you would any friend. It is a simple act to bond and you
don’t have to do anything outlandish or change your entire life around to enjoy
the company of a spirit.
You should always consult with your practitioner or seller to see if the method they bound the spirit with requires any additional steps, invocations, etc.
Speaking solely for Creepy Hollows bound spirits & bindings you do not have to do anything special or perform any specific ritual, invocation, etc in order to welcome a spirit into your home.
You can use the associations provided for entities through the Creepy Hollows Encyclopedia if you wish, and you can make offerings to the spirits in your home in order to show your appreciation for the, but nothing will replace or be more effective than time spent with your spirit & involving them in your life.