It is true in boxing and in martial arts that whoever controls the center of the ring or cage has a huge advantage. The judges in both sports see that person as the guy that is controlling the pace of the fight, and they also don’t have to work as hard to stay in a good position while fighting. One step in the center usually equals two steps if your backed in a corner.
The following video has UFC Champion Frankie Edgar teaching classic boxing footwork to cut off the cage in MMA. You can skip to the drill at 3:05.
This drill that Frankie Edgar is showing is not new, but it is a critical drill to practice often whether you are a rookie or a veteran to the fighting world.
Go back and forth with your partner and try to cut off his steps. You can either time time the drill (30 seconds each) or switch each time someone escapes.