You might think..."OK, I have a vase, so I'll put flowers in it." Yes, that is the ideal use for a vase. BUT...what do you do with a vase when it's not filled with flowers? You can fill them with other fun things like desk essentials. Or, you can use them and style them in other ways that gives them function without flowers, too. Here are a few ideas...
1. Book Ends. As long as the vase is sturdy and won't tip easily, use them as book ends to spruce up what would otherwise be a plain bookshelf.
2. Sculptural Decor. If you choose the right kind of vase, it looks cool on its own even when it's not filled. Set it out on an end table, dining table, window sill, or anywhere.
3. Hold Faux Flowers. I'm a big advocate for faux flowers when you can find some you really like. Like not flowers that are supposed to look real, but ones that are obviously faux and you can embrace their non-realness. That way, you can keep them in a vase for however long you want and feel good about it!