This one might sound silly, but when it comes to writing fiction, silliness is good.
If you’re feeling stuck, particularly when coming up with ideas, turn your writing pad around and write through the ruled lines. This works even if you don’t use lined paper – just turn your pad sideways and write up the page instead of across it. Do diagonals, if you like. Free yourself up. If you don’t normally do this, you’ll be surprised at what a difference it can make. And it does feel particularly good on ruled paper – almost anarchic*.
Try it. Write sideways, think sideways.
*You may gather from this that I am not exactly what you would call a rebel.