How to Observe
Sit in a nearby location where you have a clear view of your horse, observe how he interacts with his surroundings void of your personal emotions. Make sure you don't observe with feelings, stick to the facts. Does your horse nuzzle his/her neighbor with soft eyes? Dose he/she pin his/her ears and at what? When he/she is resting, does he/she rest more often on one foot then the other?... Download the observation worksheet to help you with this exercise.
Get yourself a comfortable notebook and pen. Write only what you see. Record the muscle movement and the relative cause if possible in as few words as possible. Get to the point.
For example: I'm observing my horse eating. when he chews, his lower jaw moves from side to side grinding the food. Food falls from his mouth when he is eating. When he is finished, he wipes his face across the railing and licks the fence to clean it up. This is a description of facts free of emotion.
Observe your horse in a place where he is most comfortable and familiar. This will help you accurately record his personal attributes. It will also allow you to observe behaviors that you may not normally see. Sit in a comfortable location, preferably out of view of your horse. This will help him behave more similarly to when you are not around.
Be very carful about "knowing" your horse in the observation exercise. Try to see him again for the first time. So often we think we know everything about our horses personality, when there is so much we haven't seen.