I use the foam balls, but only for pitching and chipping in my house. I set up a laundry basket and try to them into the basket, that way I get lots of practice while watching TV or the kids. I like the foam balls because they don't leave dents in my walls when the kids get a hold of them, or when I pull out the piece of shag carpet to practice lobs.
I also have a couple fake holes in my basement that I practice with.
I spend quite a bit of time with my brother and friends having putting competitions in the basement. We also made up a game where one guy swings a putter handle like a bat while another chips balls at a laundry basket. If the ball goes in the basket the batter is out, but he continues to hit until he gets out. You do many different styles of chips, from high floaters to screaming line drives trying to get that guy out so you can hit at him.
We have points for hitting the ball to different areas, and if there is more than 2 people playing, we have fielders. Sketchy thing is the room is like 14 ft across so when someone hits the ball at you, there is not a lot of reaction time. Hahahaha Took one in the throat 2 nights ago!!! Thank goodness they are foam balls.
On a side note, never really though much about this when we started doing it, but my greenside saves have increased as well as my putts per round has decreased. It doesn;t feel like practicing, but you really are.