Tip burn is usually caused chemicals in the water. If you are using city water for your plants it has been chlorinated, and very likely has been treated with fluoride, either of which will cause the burn. Using rainwater or distilled water will take care of this problem. We have a bunch growing in the atrium at work. I would love to start one in my office.
Spider plants are very easy to propagate.
The ideal method is to allow the plantlet to root while it is still attached to the mother plant. Set a pot filled with sterile potting soil within reach of one of the plantlets and just stand the offset onto the surface of the soil. If necessary you can pin it in place with a bent paper clip. When the young plant has rooted in 7-10 days just sever its ties with the mother. If it is impossible to use this method, look at the base of the plantlets and choose one with a very fleshy set of roots rather than choosing one with good foliage.