Gaited horses have several more "gears" than do trotting horses. As a gaited horse owner, your goal will be to "get the gait" consistently, without your horse reverting to a trot or pace. Further, you need to make sure he isn't performing a stepping pace, which is smooth to you, but will wreak physical havoc on him over time.
The good news is that training your horse to gait is as easy as 1-2-3-4: walking! That's right, you can easily learn how to walk your horse right into his best natural saddle gait.
Before you begin, make sure your horse is comfortable in his tack, and has plenty of freedom through his back. Discomfort or physical restriction of any kind will sabotage your best efforts.
Plan to ride with the impulsion aids with which you're comfortable, such as a crop, spurs, or long reins. To perform a correctly timed saddle gait, your horse has to use every muscle in his body. Therefore, you must insist on this gait as strongly and persistently as is necessary.
(Note: Avoid a gaited-horse trainer who uses shortcuts, such as unnatural shoeing and trimming, weights, chains, and other artificial aids. Such techniques can affect your horse's soundness and aren't effective in the long run.)
Get the Gait
Here's my step-by-step technique for getting a smooth saddle gait.
Step 1. Ask for an active walk. Mount up, and ask your horse for an active, vigorous walk, but don't allow him to jump up to a faster gait. If he does, apply a light rein cue to check him, while simultaneously using your seat and leg to keep the forward momentum. Ask him to walk as fast as he can without changing gait. I call this exercise "working the walk."
Step 2. Maintain an active walk. As you apply these cues, your horse might tend to pick up speed, but immediately return to a slower walk. Anticipate this behavior, and take quick action to prevent it. The instant you feel him begin to take a slower step, sit back, and use your leg and impulsion aids as strongly as necessary to maintain his speed. Tip: Avoid continually using your boot heel to bump your horse up to speed. He'll simply learn to ignore the continual, annoying nudging on his rib cage.
Step 3. Increase collection. When your horse is willingly "working the walk," begin increasing his degree of collection. This will help maintain correct form and timing, while enabling you to obtain greater impulsion and speed.
To do so, walk your horse right up to (and perhaps slightly over) the "edge" of where he can maintain the walk without breaking into a faster gait. If he starts to break, perform a halt that's similar to a "mini" sliding stop: Keep your hands low, push down into your seat, and apply leg aids while applying backward pressure equally on both reins. This will ideally get him to shift his weight back over his haunches when he halts. From the halt, ask for a couple of backward steps by continuing to apply backward rein pressure. Then halt, and allow some slack in the reins.
Step 4. Again move into an active walk. From the halt, ask your horse to again move into an active walk. Maintain light rein contact to encourage him to keep his weight rearward. This lightens up his front end, encourages him "dig in" from behind, and thereby improves his gait's speed and timing.
Troubleshooting tip: If your horse raises his head or worries the bit in response to rein pressure, lighten your rein contact just a bit. You might be requesting more collection and impulsion (which works his topline muscles) than he's ready for. However, don't allow too much rein slack, as this will allow him to shift his weight forward - and a horse that's heavy on the forehand won't be able to perform a correct gait. Your horse will better respond to your cues as he builds muscles and stamina.
Step 5. Ask for increase collection and speed. When your horse responds well to the halt and rein-back exercise (this should take only two or three riding sessions), request greater collection and speed via the half halt. The half halt is essentially the same as the halt, except that the instant your horse responds to your rein and weight aids by hesitating (indicating a backward weight shift), you maintain rein contact, and ask him to move more actively forward.
By consistently working the walk, and increasing collection, impulsion, and speed by practicing the halt, rein back, and half halt, you'll soon become your horse's best gaited horse trainer!
Is He in the Stepping Pace?
As you ask your horse to gait, he may raise his head, hollow his back, and revert to a trot or stepping pace. Such action allows him to avoid employing the big muscles along his entire topline, and just sort of shuffle his legs underneath himself in an easy, lazy amble.
The stepping pace may actually be smooth, but it's in bad form and is hard on his hocks and stifles. It also hinders your ability to obtain gait consistency.
There are two ways to tell, from the saddle, whether your horse is performing a stepping pace, rather than the correct, square gait: (1) If he jumped right up from a slow walk to a fast gait, with no "middle gear" or smooth transition; and (2) if his head is moving from side to side, rather than up and down, indicating a lateral, or pacey, gait.
Note that some horses will always have a slight inclination toward a lateral gait. But if your horse is holding correct walk form, his mane will bob up and down. Any correctly formed gait will ultimately be expressed in front via some degree of head nod or shake.