While walking and reading, it's easy to get tripped up. Reading, headset, television, visualization. I try not to have people get too complicated doing too many things at the same time, because I don't want anyone to get hurt. Just do it slow, and get some reps, get the burn. It flows in both directions.
Steppers Stay as straight up as possible.
Don't lean forward on the machine. The more you get out of your exercise equipment, in terms of enjoyment and results, the more you will use it. And the more you use it, the healthier you will be.