Default [Q] how to get rid of insufficient storage space error?

hello.i have prestigio multiphone 4055 duo.recently i havent been able to download apps from 1mobile market(uninstalled play store) or from web links.i have the app called clean master and i clear cache every day. i havent got custom rom just root apps like xposed installer and its modules,rom toolbox busybox.
what should i do?
i have 48mb sd space and 850mb internal storage space.