I'm still trying to adjust from an unlimited plan for my iPhone only and 3GB for my iPad to a shared 10 GB plan. Currently I have 5 days remaining on my billing cycle, and at almost 8GB of use. I have used mine for: YouTube, Vevo, updating and downloading apps, music, web browsing, watching shows on Showtime and HBOGo, and using apps. Most of this on my iPad. I have used 1GB at the most on my iPhone.
Sent from my AT&T LTE iPad Air. White in color of course. Or my iPhone 5s. Gold of course.
This is kind of where I am. I'm used to a grandfathered unlimited plan when it was just me, so I never even worried about data usage.