One of the most critical parts of building up the oil finish is to let the wet sanded layer dry a little increasing the thickness of the coat before wiping to a no streak finish. You must leave a sheen behind as much as possible for good build up but at the point you leave streaks it is hard to make sure you remove them with the next coat. This is especially true as you use finer and finer grit. In the beginning 320 will correct most evils quickly while 600 grit later will only polish streaks left behind. Waiting 24 hours between coats is best.