1. Clear cache: Over the course of using the various apps on your phone, plenty of redundant files tend to get accumulated in an area of local storage called cache. While these are important during app use -- while browsing, accessing Facebook etc -- these temporary files can be safely deleted later. Go to Settings | Storage and USB | Internal storage. Tap ‘Cached data’ and clear it -- this could free up hundreds of megabytes.
2. Delete downloads: Files you download to your device remain in the downloads folder until they are removed. Search for ‘Downloads’ from the search bar and open the Downloads app. Ensure there’s nothing you require in the list that appears. Now long press any file and from the menu above tap the three dots and choose ‘Select all’. Hit the trash icon and it’s done.
3. Use Google Photos: One of the most significant features of Google Photos is the ability to clear photos from your phone that are already backed up to the cloud. Launch the app, tap the burger icon on the top left, then tap ‘Free up space’. This could potentially clear a ton of space on your device.
4. Find the large folders: It is always easier to visually see the distribution of large files on your phone -- use a free app called DiskUsage to do this. Use this tool to quickly spot and delete those movies that you forgot about, liberating plenty of storage in the process.
5. Format the SD card as internal storage: In Android Marshmallow and up, you can format the device’s SD card so the system sees it as part of internal storage. This effectively creates a contiguous stretch of space so you don’t see the memory full message again. Go to Settings | Storage and USB, then tap the SD card. Tap the three dots on the top right and select ‘Format as internal storage’.
