Know your area

Before we get to the plans, to get the best deal you need to make sure you have the coverage that you need. This makes it very hard for us to give a blanket recommendation of any one carrier. T-Mobile's service in New York may be excellent, but if you're in rural Iowa, Verizon is more reliable. 

Your mileage may vary, but the good news is that these networks are growing and improving all the time, particularly as the three major players race to blanket the U.S. with 5G. It's quite possible that you left a network complaining about its sparse service a decade ago, but now it's beefed itself up because of that race to acquire customers.

If you know any friends or family in your area that already use the carrier you're considering, ask about their experience. You could also go to a carrier's store and see if they offer any free ways to try out the service before switching over, such as T-Mobile's Network Pass. Verizon offers a similar 30-day program while AT&T has recently introduced its own 30-day eSIM free trial option for sampling its network.

Know the prepaid phone plan promos and deals

As with the leading carriers, there are periods when the prepaid players offer deals. Boost Mobile used to run a promo for new customers that let you get three lines with unlimited talk, text and data for $90 per month ($30 per line) after "your first payment of $100." It has since added a new unlimited plan that is $25 per month for new users, although each line must be separate and can't be grouped on a family plan. 

Some prepaid providers will even give discounts on buying a new device, but unlike the leading carriers, don't expect the same big promotions offering a free new iPhone or Samsung's latest Galaxy. Those deals are often tied to 24- or 36-month installment plans, which prepaid -- by its nature -- doesn't offer.