Inspiration often runs out.
The job you are working on is your inspiration. That is your starting point and end point. Use what the client wants to say as your inspiration. If you keep that in mind and know what you need to communicate, then, I won’t say the rest will come easy, but that is your voice.
I find inspiration from the brief. Often if you’re struggling to generate new ideas, it’s possibly becasue you lack direction. Revisit the brief with fresh eyes and if that doesn’t help, maybe go back to the client with more questions to help clarify the problem.
Best answer I have, already posted in another thread: