Water thoroughly and then do not water again until the top inch of soil is dry. Never let the Areca sit in water for more than an hour or so. Arecas are very sensitive to hard or alkaline water. If your local tap water is this way, then switch to distilled or filtered water for the Areca.

Also, avoid fertilizing it. Temperatures should stay above 60 degrees. It also doesn't fare well in low humidity. Finally, it is very prone to spider mites. Check the undersides of the fronds regularly for signs of spider mites (dust-like particles under the leaves). Misting helps deter mites, but doesn't make much difference as far as raising humidity. If any of these conditions are not right, the areca reacts by getting brown tips and yellow fronds.