I can only speak from experience, but for me the best way to get over a creative block is to stay in motion. Immersing yourself in a state of flow can unleash a maelstrom of creativity. The hard part is having enough self discipline to sit down and say "Okay, today I'm devoting 30 minutes to my craft even though I have no idea what i'm going to make, even though I really don't feel like it right now". The key is to let go of all expectation and trust that whatever you're creating needs to be brought into existence even if it isn't worthy of an audience.
Ideas lead to other ideas. And theres no way you're going to get to the good stuff, without exploring the obvious, cliche, and shitty concepts in your head. And yes, you have to actually EXPLORE them. Writing them down in a notebook is a good starting point, but it's not enough. We're all capable of having amazing, innovative thoughts, but unless you act on them and create something tangible, they don't mean anything. And nine times out of ten, that perfect idea requires a little more nurturing than you intended.
I read somewhere that great artists and designers aren't the ones with the best ideas, but the ones who created the most & were able to learn from their process and get to the really good stuff. I can't help but agree.
Allow yourself to be great - create more, even if it's not in your preferred medium. If you're a visual artist, why not try to make music? You don't have to share it with anyone! Just know that it's part of your process, and you're learning by staying in motion.
I challenge you - create something (anything!) everyday for 3 weeks, and I promise you something beautiful will come out of it.