Smartphones are configured at the factory to optimize such factors as display quality and data-connection speeds. But these default settings might not meet your needs as well as you'd like. These seven steps will help your improve your smartphone's battery life, make it work faster, protect your privacy, cut your phone bill, and even improve what you see and hear.
1. Extend Battery Life

Make sure the screen brightness is set to Auto (on most iPhones, go to Settings, then Display & Brightness), so the device can adjust to indoor and outdoor conditions. But lower the baseline brightness (usually by using a sliding switch in the Display menu). Set the screen to sleep after 15 or 30 seconds of inactivity. If you’re in an area with no signal, turn on airplane mode. If possible, reduce the update frequency of email, social-network feeds, and other apps to once every hour or so. Check out these 9 mobile gadgets with long battery lives.
2. Improve Voice Quality

People have long complained about cell-phone voice quality. The HD Voice feature promises to help you converse with the clarity of a face-to-face meeting.

HD Voice works by transmitting calls over wider frequency ranges, with a higher number of audio samples carried per second. But you have to turn it on—HD Voice often is off by default.

Check your phone’s Settings menu. On iPhones, you can turn on HD Voice by selecting Voice & Data in the Enable LTE sub menu of Cellular settings. On Androids, it’s a little more varied. For instance, on some Verizon handsets the HD Voice switch, called Advanced Calling, is next to a green square with the letters “HD” in it. Depending on the phone and the carrier, the controls may also appear under headings such as  “noise reduction,” “personal call settings,” or “VoLTE."

But before you get excited about HD Voice, you should know that its benefits extend only to people talking on compatible phones within a carrier's networks. So, for example, Sprint customers won't be able to have HD Voice-quality conversations with their Verizon friends. Don’t fret if HD Voice is not yet an option on your phone or from your carrier. You can also improve the sound by maxing out the volume on your phone app (not the same as the volume control for multimedia playback, which won’t raise call volume). Also, adjust the position where you hold the phone—experiment to find the sweet spot where the microphone and speaker both seem to work best.
3. Restrict GPS Tracking

A smartphone GPS mode is great when you need directions or want a local restaurant review, but you may want to restrict marketers from accessing your location data.

To enhance privacy, iPhone users can go to Location Services in the Privacy section of Settings. Take a good look at the apps listed and review their GPS privileges. Make sure you switch GPS on for mapping apps and perhaps for weather or shopping apps, and to Never for apps that don’t really need to follow you in order to serve your needs.

Android 6.0 Marshmallow users can go to the Permissions section for each app in the Apps section of Settings. On phones running versions of Android 5.1 or older, you’ll have open up each app to change location tracking and other privileges. Unfortunately, many apps take an all-or-nothing approach, so you may have to remove some apps entirely if you don’t want them accessing your location data.
4. Make It Easier to Read and Type

Apple and Android phones have Accessibility menus in Settings where you can adjust screen brightness and the look of text.

On an iPhone, go to Accessibility in General Settings to find controls for making text larger and bolder, as well as a switch called Button Shapes that makes navigation controls more prominent. You can also experiment with the Settings designed for users with hearing and visual impairments, whether you fall into that group or not. You can make app icons a tad bigger by activating the Display Zoom feature in the Display & Brightness section of the main Settings menu. And to reduce distractions, move the icons for your favorite apps to the home page and stash the rest in a folder in the corner.

When it comes to Android phones, easy modes on many LG and Samsung models automatically boost the size of app icons and fonts, and make the interface more senior-friendly by paring features down to the essentials. If you phone lacks such a switch, you can also experiment with the settings for users with hearing and visual impairments, typically found in the Accessibility submenu within settings.
5. Save on Data Usage

Because transferring data via cell service is expensive, you should try to use Wi-Fi whenever possible to back up or share large files (photos, streaming videos, etc.). You can also adjust the settings for individual apps to prevent them from downloading news or updates until you’re on a Wi-Fi network—ideally one you trust (think home or office).
6. Turn on Bluetooth Sharing

You don’t need to fumble with e-mails and attachments when the friend with whom you want to share a photo, video, or any other type of file is standing right in front of you. You can just beam it directly, phone-to-phone. On iPhones, this trick is called AirDrop, and you can access and turn it on from the iPhone Control Center (an upward swipe of your finger from the bottom of the phone screen). Make sure you friend has Airdrop on as well. Both your friend and you will have to make yourselves discoverable by selecting Contacts Only or Everyone. Then, from the photo or document select the sharing button (the symbol is a square with an upwards pointing arrow in it.) and tap AirDrop. Your file will be transmitted to your friend via Bluetooth.

Androids phones have a similar feature called Android Beam, which also uses Bluetooth to transmit photos and other docs. This system uses NFC, the short-range radio technology that enables mobile payments at the register by bumping your phone against a special terminal. This time, however, NFC launches Android Beam when you bump the phones together. You’ll find the switch for Android Beam in Settings. And, as with Apple’s AirDrop system, both you and your friend will have to have this feature on. Bummer: AirDrop only works with Apple devices, and Android Beam works only with Android devices.
7. Back It Up

Many of the things you do on your smartphone, like e-mail, calendar appointments, and Facebook updates are backed up automatically up to the cloud in an account. Photos and videos can be, too, but you have to take steps to make that happen.

Apple’s iCloud Drive, available to any device that can access an iTunes account, provides 5GB of free storage. Go to Settings, then iCloud, then Photos. Flip the switch for iCloud Photo Library. Google Drive provides a more generous option for both all smartphones, including iPhones: 15GB of free storage. All you need is a free Gmail account and the Google Drive app on your phone.

Also consider downloading Google Photos, which lets you set up automatic photo and video backups, and provides a great interface for viewing, editing, and sharing photos. Get more details about backing up your files.(from YAHOO)