There is a war story told of James Garner, where patrols he led always returned, while others got cut up by the enemy. His commander wanted to know why, and cornered him, and questioned him as to why this was so.
James was reluctant to explain. For it seemed he could smell the enemy, before contact. James HATED garlic! And the enemy reeked of it.
His commander was startled into thinking, "perhaps they can smell us too?", and in typical military method, FORCED our troops to eat garlic, so we would smell just like the enemy.
( completely negating the advantage)
(Now, I have know this story for many years, since before he did the "steak, it's what's for dinner" commercials. I have not researched it, but the story is true as far as I know. So, YES, garlic can give you away, at least to men, perhaps to deer)
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.