Originally Posted by Strange
Really, it's all about perfecting your eye. If you get a chance, I suggest hopping on other horses and jumping a bit too. Just because you can find a distance on one horse doesn't mean you can on them all! The more flexible you learn to be with your eye, the better you'll be at finding distances.
This is so so so very true. I've had my gelding a little over a year now and my trainer thought it would be "fun" to have us all switch horses during our jumping lesson. I ended up riding a big strided warmblood. I couldn't see a distance to save my life. And I hardly ever miss on my own gelding. So it was quite a rude awakening!
As for seeing distances on my own horse, I watch the fence through the space between his ears. By the time I'm about 4 strides out, I can usually tell where I expect the front rail to be in relation to his ears. I know it sounds a little nuts... but it seems to work out well for me.