Many Android apps use stored - or cached - data to give you a better user experience. Cached data can save a little time (and mobile data), but the files stored in app caches are for convenience and are not strictly necessary.

• To clear cached data from a single app, go to Settings > Applications > Application Manager and tap on the app you want to modify. In the app's Application info menu, tap Storage and then tap Clear Cache to clear the app's cache.
• To clear cached data from all apps, go to Settings > Storage and tap Cached data to clear the caches of all the apps on your phone.

• Your Android phone has a downloads folder where everything you download - photos, videos, documents and other files - is stored. Delete unnecessary files to free up space.
• You'll find your downloads folder -- which might be called My Files -- in your app drawer. Tap and hold a file to select it, then tap the trash can icon, the remove button or the delete button to get rid of it.

• Google Photos lets you back up every single photo you take with your phone directly to Google Photos, and it will not count against your Google Drive space. Once your photos are backed up, you can delete them from your device to free up space.
• You will need to turn on Google Photos' Back up & sync feature to take advantage of all this free cloud storage space. To do this, open the Google Photos app and go to Settings > Back up & sync and turn it on.
• Once you've backed up your photos using Google Photos, you can go to Settings > Free up device storage, and Google Photos will delete any photos and videos that have been backed up.

• Apps probably take up most of the storage space on your phone. If you've got an Android phone that lets you add a microSD card for extra storage, you may be able to move some of your storage-sucking apps to that microSD card.
• To do this, open Settings and go to Applications > Application manager and tap the app you want to move.
• If the app can be moved, you will see a button that says Move to SD card -- tap this button to move the app to the microSD card. (On some phones, you may have to tap Storage to find this option.) Only part of the app will be moved to the microSD card. How much of the app will be moved depends on the app and, unfortunately, many large games will not move a significant portion of their data to the microSD card.

If you've tried all of these tips and you still need more space, there's no getting around it - you're going to have to start deleting some things. You've probably got some (maybe several) apps on your device that you never us.