Ok, first thing you can do is to stop automatic updates in settings, because some apps do updates sometimes daily. Set it to first ask for permission to update or only update when wifi is available.
You can also stop all wasp services that sneaked through on your phone. Each carrier has its own codes for that.
Then in settings in the data usage section you can go through each app listed and look at the bottom where it shows a background activity box. Tick or untick as you see best. Daily apps should best be allowed performing background activities, like browsers, but some are a real pain in the butt and slows down your phone a lot. I even bar Google Play Store and only untick it temporarily if i want to do app downloads, but if you want to be rather careful leave them be.
It is answered already....
After reporting and logging a complaint 2 weeks ago, I were informed one of our 2 towers had major problems. But they either could not or would not tell me which tower closest to my house it was and that they were working on fixing it, to which I told them to work harder. Miraculously last week I had decent reception again. Loads of emails came through all at once. I could receive calls again, I could access the Internet relatively easier and I could send out emails 
