Brown tips can come from a variety of mistakes.
1) too much water; tips are brown, but succulent
2) too little water; tips are brown & dry
3) too little humidty; put other plants
or wet pebble trays around the plant
to add moisture to the surrounding air
4) tapwater; if you water with unfiltered tapwater, the minerals in the water can cause brown tips
When I first started keeping houseplants, I had brown tips. I worked on the watering until I could tell the plants
were happy. Still brown tips. Got some houseplant books; read about the tapwater; began using filtered water or distilled from the market. No more brown tips.