[iMore Question]

My iPhone 6s has full storage so I purchase more iCloud memory but I still can't take pictures or download apps because it says to manage storage. I do have pictures etc shared to iCloud.
iCloud says I still have 48.8 GB available but I'm not sure how to utilize it. I don't want to have to use my data plan to listen to music

[Tartarus]

If you hadn't already, please enable iCloud Photo Library in Settings > iCloud > Photos. In that same settings screen you will see the option to optimize iPhone storage. Enable that one also. This will save some space on your iPhone.

But, first of all, please remember that by buying extra cloud storage, you are technically not expanding the storage on your iPhone, just on iCloud itself.

To free storage space on your iPhone you will have to delete some apps, photos and videos and other stuff.