Sorry, wrong number
Make sure you aren't billed for the first minute of incoming calls, so you don't have to pay for misdialed numbers.

Customer service woes
Wireless customer service is said to be suffering. To get a sense for how you will be treated, call them first -- on the customer service line, not the sales line.

Distance yourself
Consider carriers that have a national network if you expect to dial long-distance often. Rates can be more competitive.