The two most common are the use of the data usage meter or my data manager app. The first is what comes inbuilt into the device while the second is a mobile app that can be downloaded from an app store on the internet. The question most people struggle with is whether there is any value in investing in an app when there is already an inbuilt solution designed to address such issues.
The inbuilt meters have been shown to lack accuracy. This is because most of them only monitor explicit usage by the device owner when creating their logs of the data consumed. This creates a discrepancy between the statistics that the network operator is using and those that the phone shows. The mobile app has the advantage in that it will measure the background streams of data that apps are sending using the permissions that have been set into the device. Background data streams are created by apps using the permissions that you normally agree to as you accept the service agreement or end user license agreement of an app that you have bought.
My data manager app is better at providing an accurate view of the data consumption in the mobile device. This is because it is able to break down the statistics of consumption clearly for different apps. This is quite useful where one seeks to determine the apps that, while not quite needed, consume a large amount of data. The app also allows you to manage your data connection from the same place. This is because, in most cases, Smartphone users have found that the most effective way to control data use is to switch it off when not currently in use.
Data usage meters have another challenge in that the statistics they provide are usually quite cut and dry. They will inform you how much data you have consumed but not while doing what. This can be challenging to the person seeking to gain a better understanding of the operations concerning data on their phone. There is a silver lining to all of this in that there is no reason why someone must only select one. You are quite free to use them both and compare their performance before deciding whether to keep it or not.