always keep changing up your exercises with your horse. I rarely work my mare on the pattern outside of a race or rodeo. One exercise I used to do with the kids I gave lessons to was set three barrels up in a straight row as far apart as you are comfortable with and start by weaving them and asking your horse to pick up their shoulder with both leg pressure and hand cues. Then move on to asking them to circle all the barrels one way and then the next, making sure that their body position is correct and they are working off their hind end to make the turns, crossing over in the front, etc. A good way to work on correct body position for the horse and for yourself with your body position, hands and feet at a slow pace.
Other than that, take your horse out on rides away from the arena and barrels. Let your horse be a horse and not have to circle barrels or poles all the time. That's on the most important things to do with a barrel horse so they don't go sour.