Consider comfort. Smaller, lighter headsets are generally more comfortable than bulkier models. Most headsets have an ear clip or hook to hold them in place, but some of the smallest models insert into your ear canal. While that makes them less obtrusive, they can easily pop out if the fit is less than perfect. To improve the chance of getting a good fit, look for headsets that come with an assortment of ear adapters.
Seek out high voice quality. Most of the Bluetooth headsets we tested had at least good voice quality, which is adequate for most situations. A model that has very good voice quality would make it easier to converse in noisy or windy environments. While some models with this feature performed well in noisy environments, others didn't.
Expect setup time. Bluetooth headsets and phones need to be electronically introduced, a sometimes-tricky procedure known as pairing. Some headsets allow you to initiate the process with the press of a button. Typically, Bluetooth headsets can pair with only one compatible device at a time. And if you want to connect your Bluetooth headset to another phone or computer, the headset must sever ties with the original device before it can pair with a new one. Some headsets make pairing much easier via a feature called multipoint pairing, which lets you pair the headset with multiple devices, automatically connecting with whichever device is active.
Consider charging convenience. Like other portable devices, Bluetooth headsets have batteries that run down, adding to your menagerie of mobile devices that require recharging. Models with ample talk time on a charge minimize the need for recharging. While many headsets let you gab for about 8 hours or more between charges, others run for less than 4 hours. Nearly all come with a wall charger; some include a cable for charging via a computer's USB port. Others also include a car charger that otherwise costs $10 to $30. Nearly all headsets indicate when charging is complete. An audible and visual low-battery warning is also important.
Look for useful features. All mono headsets are designed to work in either the right or the left ear. Most headsets have a microphone mute control that prevents the caller from hearing what you say but allows you to hear the caller. Call hold mutes the call on both sides and is handy if you want to talk face-to-face with someone else without ending the call. Volume control and last-number redial are also useful. A plus for music lovers: stereo models that allow you to replace the ear buds with better-sounding ones. Be aware that some headsets might not support some phones or some of their features. Check with the headset manufacturer to confirm that the unit is fully compatible with your phone.