The route to Jeuno begins in Tahrongi Canyon. Windurstian's pilgrimage to the central city is the easiest of the three, but don't get cocky. In Tahrongi Canyon, be sure to check the crystal at the Crag of Mea, so you can teleport here later. With that out of the way, head north to Meriphataud Mountains.
Meriphataud Mountains is barren not only of plants, but of aggressive monsters as well. Simply follow the road north the entire way, and you'll be one step closer to Jeuno.
Sauromugue is perhaps the most dangerous of all the areas on the way to Jeuno, so take extra care when moving around. Follow the road, but don't be afraid to stray to avoid monsters as long as you keep the road in sight. Head to the northwest, avoiding the Yagudo, Tabar Beaks, Tigers, Goblins and Raptors. All of these attack on sight, and it's a long road.