I practice regularly at distances up to 40 yards. 90% of my practice, however, is at the ranges at which I plan to hunt: 20 - 30 yards. The reason I concentrate so much of my practice at those distances is that I shoot instinctively. The only way you're going to shoot accurately instinctively is to shoot a lot of arrows at the distances at which you plan to hunt, similar to practicing with a basketball at all your likely shot distances, or throwing a football through an old tire. When I shoot at 40 yards or further, it's more for fun or in case I decide to shoot in an archery competition, so I can keep the arrows in the general vicinity of the target.
If I were shooting using an aiming method, gap, etc., or shooting mainly to practice for tournaments, I would probably spend more time shooting at longer distances.