We stretch out our horses every day we ride, twice: Once before we ride, and once after, to keep them loose and comfortable. It's very important to make sure their muscles are warmed up, just like if a person were going to do strenuous activities. It's also important to hit a full range of motion in their legs, stretching everything from the hock (right above the hoof) to the withers (right below the neckline).
Another huge aspect is perfecting our training. This is where the cues get really specific, and you have to be extremely hard on yourself to maintain a flawless, consistent pattern. Remember that you have to look to the same spot, have your hands in the same place, say the same commands in the right spots, push with your legs at just the right time, all while going up to 40 miles an hour. It can be a lot to keep track of, and is very hard to master. A lot of barrel racers take this time to examine the scientific aspect of barrel racing: they look at aerodynamics, the exact best place for the horse to make their turn according to their body shape and leg length, and they start looking for the smallest, simplest ways to cut off 100ths, even 1000ths of a second off their time.
All in all, there's a lot left to do before the first show...check in on it later!