First of all, brush them in the direction they grow, because that is how they will lay. Grow them for 4 weeks and only do them every 4 weeks. This does not mean it will ever be easy, sometimes we just have a challange. Those straight up hairs apply the wax in an upward sweeping motion as much as possible.
When all else fails, don't worry about it, continue to pluck her to death if you must and just be sure to charge her.