I'm between books right now. I have a novella on submission and another novella waiting to be edited. For the first time in a while, I don't have an idea ready for my next book. That's okay. Ideas are plentiful. And there are no brand new story ideas. Everything's been done. That doesn't mean there aren't new and fresh takes on stories.
Waiting to write until you have a perfect, blockbuster idea isn't necessary. What makes a concept fresh is your take on it. Your voice, your outlook, your background, your experiences, the characters you create, and the way only you can tell the story. The late Richard Laymon referred to the unique way a writer tells a story as their "Secret Sauce." To illustrate this, let's take a well-worn horror antagonist, the vampire. Laymon told his own unique vampire tale in The Traveling Vampire Show. Contrast that to King's Salem's Lot. Both are vampire stories. Both couldn't be more different.
Laymon showcased his vampire in a carnival sideshow atmosphere. King brought his vampires to small town Maine. Both writers have distinct voices and styles. Two takes on the same idea, both very different. If you were to write a vampire story, how could you make it your own? Make it fresh? Something we haven't seen before?
You could play with some ideas, placing vampires in different scenarios. Richard Lange, in his excellent vampire novel, Rovers, features a vampire motorcycle gang. Chuck Wendig's Double Dead puts a vampire in the midst of a zombie apocalypse. What about a retail chain that employed vampires? Or a vampire amusement park? A secret military unit made up of vampires? What if vampires moved into your town? How would that play out? The possibilities are endless.
The important thing is to pick a concept that excites you and put a fresh spin on it. Ideas are plentiful. Write the type of story you'd like to read. Then tell the story only you could write.