When I was a kid, I had a juggling video from Dave Finnegan. On it there was a song that went, "I hate to tell you, but to tell you the truth. You should learn to juggle in a telephone booth. Don't hit the ceiling, the walls or the floor. And whatever you do don't walk out the door!"
Stupid? Yes. BUT there is a good point there....you have to keep the balls close to your person. In all seriousness, I'd practice over a bed. That way, if you drop the balls--and you will--you don't have to bend all the way down to pick them up.