I got same problem with you, I'm using android phone and sometimes my phones got freeze and I must restart my phone for normal using. you need to check some apps, it might not compatible with your phone device, should remove those apps for best use
I have ways to optimize your phone for running efficiently
using Swapper 2 to increase vitual RAM for your phone, also removing apps hidden running
move apps to SD cards for managing easily and increase internal your storage.
hope it helpful with you :
I would suggest you disable all useless apps which are pre-installed and cannot be uninstalled. Try moving as many apps as you can to your SD Card. Use clean master to scan and clean your phone of unwanted space.
Finally, if nothing works then root your phone to enjoy great speeds