I printed DXF1985's Rose. But the stem is kind of short for a vase, and the rose is top heavy, making it hard to display.

I drew up this holder in Fusion 360, with the idea or it looking a little like the top portion of a vase. Not too elaborate, as I am still kind of new at modeling, but it works well as a base.

Update March 4th 2019: It was pointed out that I left the date on the bottom of the .stl file. I am replacing the stl with a new version. No text on the bottom.