One of the nicest things that I think you can do for someone is to improve their home for them while they’re away somewhere. When they return, they get to come home to a place that is nicer than when they left it.
I’ve done this a few different times for people who were away from home for awhile. One time I had a friend who went to a Florida drug rehab center for several months. A group of us got together to make her apartment’s kitchen nicer while she was gone. We didn’t make any huge changes but we cleaned it up and added a few new appliances. She was even more thrilled than we thought she’d be when she got home and saw what we’d been doing while she was away.
It’s important to note that you probably shouldn’t make any major changes to someone’s home without knowing for sure that it’s what they’d want done. A home is a person’s sanctuary so they don’t want to be startled by a drastic change. Make changes like adding furniture and fixing torn curtains - things that will be appreciated and can be easily undone if the person doesn’t like the new design.