Roughly once a year I do a factory reset on my Android based phone.
Before I do this, the main thing I check is that I have anything I would like to keep backed up or copied off, such as contacts, photos, videos and any note based applications. I generally don't play games, so am not sure what would be involved to backup game scores.
I then carry out a full reset and set it up like as if I just upgraded my phone, restoring my contacts, e-mail settings, etc.
Although it can take an hour or two to go through this process, I still find it quicker than endlessly trying one cleaner tool after another. There was one cleaner tool (can't remember the name) I got from Google Play that got my phone stuck in a reboot loop, which took quite a while for me to figure out how to resolve.