Buy the best smartphone you can afford. The quality of the camera and the processor speed matter a lot. As the phone gets old the battery ability to store charge gets less and less.
Which phone features do you want? You should be able to answer the question. Some phones have features you may not use and you pay for them when buying the phone.
Does the phone reflect your personal sense of style? You will spend lots of quality time with your phone ensure that you are comfortable with the way it looks and how it feels in your hands.
Screen size -Large screens (5 inches or greater), Medium screens (4.5-4.9 inches), Small screens (under 4.5 inches)
Processor – the heart every phone. A fast processor has a big impact on overall performance, such as how smoothly a phone handles flipping through menus and running home screens.
Camera – check the megapixels, and the lens quality, which could aid the sensor by exposing it to more light.
Battery - talk time, standby time, or how many hours you can expect a device to perform tasks such as playing video and music. 1,700mAh and go all the way up to 3,500mAh.
Some mobile phones use:
Apple iOS which runs on Apple. iPhone only and is good for apps.
Google android which is good for apps and the most common in the market today.
Microsoft windows which is good if you are doing lots of work on your phone.
Blackberry OS which is good for email and web browsing but doesn’t support lots of apps.