1) ANGLE IS EVERYTHING!!! Model horses are small and are not as big as a horse. This being said, you want them to look like they are full size horses. In order to do this you have to angle your camera to make the horse look life like. One thing you don't want to do is make the model horse look puny or smaller than it is. This makes the model horse really small and the horse does't look real. But how to you fix this?? :0 You fix this by learning CAMERA ANGLES!!!
Ground View-Don't be afraid to drop your camera in the grass (as long as it's not wet). Point your camera up facing the model, but don't tilt it to far because you won't get the model in the picture. Get the grass in the shot. Grass makes it realistic and it looks like your "watching" the horse.