The slowness, if it is the phone itself and not the data you are referring to, then you can speed that up by...
1. Closing (not just exiting) apps when you are done using them.
2. Making sure many apps that are on the device are not set to run in the background the second you start up the phone.
3. Uninstall any apps you don't want or need (unless needed by the phone).
4. Disable any apps that you don't want or need (again unless needed by the phone) if they won't allow for uninstalling.
Now if you are taking access being slow (internet, etc.), that one you would have to discuss with your carrier/service provider.