Fences/ Walls/ Railings
We learned by riding around a tennis court fence. It works really well because you can ride around the inside while hanging onto the fence until you get the hang of it. After an hour or so, we were able to ride along the fence, hitting it for balance every few inches. You can also use a regular wall, chairs, dorm hallways, railings, or a low ceiling. Tammy's room has a really low ceiling and she can flatten her palms against it when she is on her uni. Instead of balancing using an object on the side, this way you get support from the top. We think monkey bars would probably work well too.
Our uncle Dave uses his car for balance. (It's probably best to stay away from limos!)
Using ski poles, brooms, crutches or canes is another way to learn. Eventually you will get good enough to go without the supporters.
Some people find it easiest to use another person as a supporter. This doesn't always work, as you may not be able to find someone willing to help out. However, since we learned together, we helped each other and it worked quite well. First, the helper or two helpers should walk beside the unicyclist, hanging onto shoulders. Once the person has better balance, place the beginning unicyclist between two experienced riders. Then, the middle person can hold onto the others' shoulders and arms for support, and everyone can ride together. It's easier because everyone is going the same speed and it's smoother.
Dave rides between two people.