combine families itunes accounts

Over time, this family has grown to now everyone having their own individual devices. We each have an iPhone and a couple iPads in the house in addition to individual computers. The issue is always our iTunes accounts. My wife and I share one for purchase, but my kids have their own that I manage for them. This is getting a bit cumbersome. Is there a way for me to create accounts for my kids that are somehow under mine? I know that I can give them allowances, but that appears to be a monthly amount and I'm not willing to give them that. For the most part their purchases are from gift cards they receive. The combined accounts create some awkwardness with iMessages too as many of us can see each others conversations depending on what device we are using. In otherwords, the computers often mirror the conversations on our various phones.

Any resources out there for managing a family of iCloud accounts and devices?

Thanks much

Dan