Expand your memory – by simply adding a MicroSD card to your Android phone
Delete unused Apps’ – if you need them in the future you can simply download it again!
Back up camera pictures – back up to your pc, to the cloud or consider some third party options like Dropbox or Google Drive
Delete your old messages – generally text messages don’t take up loads of space. But when lumped together all your conversations from the likes of SMS, Facebook Messenger and WhatsApp it can add up