Mastering the mounts and dismounts required in cyclo-cross takes practice and lots of it. Start out slowly on a smooth surface; as you improve, try practicing on progressively less friendly terrain.
Dismounts: When you begin a dismount prior to an extended running section, your hands should be on the tops of your bars, your eyes looking forward, your left pedal down. Remove your right foot from its pedal, then swing you right leg over your rear wheel. Bring your right leg forward, between the frame and your left leg; simultaneously, release the handlebars with your right hand and grab the middle of the down tube. Just as your right foot is about to make contact with the ground, flick your left foot out of the pedal; pick the bike up with your right hand; plant the middle of the top tube on your shoulder; let go of the down tube; and reach under it to grab the left side of the handlebars, near the left shift lever. Remove your left hand from the bars and run like hell.
A dismount for a single lift over an obstacles is a little different. Begin your dismount as before, but when you take your right hand off the bars, grasp the top tube in front of the tip of your saddle. Execute the rest of the dismount, but maintain your grip on the left side of the handlebar and the top tube, then pick up the bike and hurdle the obstacle.
Remounts: When taking the bike off your shoulder, grab the left-top side of your handlebars with your left hand; move your right hand from the bars and grasp the middle of the down tube; then slide the bike off your shoulder and gently place the wheels on the ground, pointing in the direction you want to go. Take your right hand off the down tube and grasp the right top side of the handlebars. Always looking forward, take a few quick steps and leap off your left foot with just enough height to clear your saddle, landing on the inside of your right thigh and slipping smoothly atop the saddle (it’s easier said than done). Quickly find your pedals, flip them over and insert your feet. Normally, when you put your bike back down, the pedals will end up in the same spot each time. Try it! For remounting after a single obstacle, take your right hand off the top tube and put it back onto the bars. Now take a few quick steps and leap off your left foot and slide back onto the saddle. Find your pedals, put your feet back into them and start pedaling.
Racing: On race day, arrive with enough time to register, review the course and warm up. The course review is your opportunity to figure out how the course suits you. Take a good look at the approaches to the dismounts. Decide whether to get off your bike several meters before the obstacle or right at it (try both to see what works best for you). Remember, the keys to determining what’s best are energy-efficiency and speed. Sometimes it is too difficult to wait until the last second to dismount, event if it means running that couple of extra meters. Under these circumstances, you are eliminating the risk of an accident.
After examining all the dismounts, decide where you will remount your bike. Pick the smoothest spot to set the bike down, remount and put your feet back into the pedals. This will increase your efficiency and make it possible to start pedaling with full force immediately.
Consider what gearing you’ll use throughout the course, paying particular attention to the sections where you will have to preshift. This could mean shifting into the gear you will need at the top of the run-up before you dismount at the bottom. Decide where you can go the fastest, and make your attacks there.
If the course lacks a designated pit, or service area, decide which sections of the course are most likely to cause a crash or mechanical and place your spare equipment just beyond it. Practice bike exchanges with a friend who can help out as your mechanic on race day.
Once you’ve studied the course, it’s time for a warm-up. It is important to have a good warm-up for cyclo-cross because races are only 30 minutes to an hour long, so once the gun sounds, you need to be ready. Your warmup should take no less than 25 minutes. Include a few sprints, a little tempo work and stretching. Find a good spot on the start line and get ready for the fun.
Tactically, the best way to ride the race is to divide it into thirds. The first phase is the start – you have to go as hard as you can, jockeying for position. In the second third, catch your breath while evaluating how well you have done (this will take longer for some people than others; try to keep the "rest" interval as short as possible). The final phase is the race to the finish. You have two choices here; Defend your present place, or try to move up. Whatever you decide, it will require total focus until you cross the finish line for the last time.