1. Just because you are riding your instructor's most challenging horses does not mean you can go out and buy an "advanced" horse. Step down a couple of levels at least for your first horse.

2. If your gut says yes and your trainer says no, don't buy. If your trainer says yes and your gut says no, don't buy. Ideally find somebody to go horse shopping with you *other* than your instructor (who may want you to continue lessons, and you *should* consider lessons), and push you into being overhorsed, or the person who owns the barn you plan on boarding at, who has an incentive to find you a horse quickly. Find somebody who has no dog in the fight.

3. Always imagine the horse in plain bay. Color is fine to take into account if all else is equal, but don't be blinded by it. At the same time, four white socks don't mean an unsound horse and chestnut mares can be perfectly quiet...ignore color superstitions.

4. Never try to shove a round horse into a square hole. So many horse problems exist because the horse and rider have different goals. Don did already say this, but a horse with stage fright (they exist) will never make a dressage horse. Don't buy a horse for jumping that doesn't enjoy jumping. You and your horse should want the same things when you work together, perhaps not in the details, but in the big picture.