So simple. Is it too plain? Here is a sweet notecard I made. The red square (gift) was cut from a paint chip card that I pop-dotted for extra dimension. A sweet gingham ribbon tops the box. Inside, the message says simply, in sans-serif (plain) font, "happy holidays".
I imagine you could do much the same thing using other colors and appropriate ribbons ... a festive ribbon in multicolors atop a yellow box might be suitable for a birthday card, for instance.
Well, it was quick to do! It took longer to post this note about it than to make it, for sure!