A rule of thumb is that if you enjoy the activity often the other person will also. Celebrate special events. Have a party. Decorate his or her room for an upcoming holiday, like Valentine's Day. A back rub with wonderfully fragrant cream might be very welcome.
Many institutions have pastoral visits on request.
Gardening in the room or recreation area can be fun and a relief from the monotony of the institution. Be a willing listener and a shoulder to cry on. Some days are better than others. Remember that it is a great act of love to visit and stay involved. If it is not a good visit then don't personalize it.