This simple trick will get you unstuck.
An idea captures your imagination, the muse strikes hard, it feels that nature itself has channeled its creativity through you. You get excited and you sit down to put that brilliant idea into a magnificent masterwork.
You raise your index finger firmly place your hands beside your typing pad, for the first letter of the first word of the brilliance. But, that finger remains hanging up in the air, that letter just won’t come out, it’s that shy kid that flaunts himself at the back of your mind when no-one’s looking.
Don’t worry every writer has that kid inside and it might look like a failure to not give a form to that kid. But know this, that kid is not ready yet, it needs to be worked hard on, to create a genius that is you.
So loosen that firm hand and start working on another idea that you can easily produce, no shame in it. That stuck idea will show up later in a more executable form. Even if that kid does not show up again, you would have done so much more with your craft that it won’t matter before the treasure trove of ideas you dug up by diligently working.
The difficulty lies not so much in developing new ideas, as in escaping from old ones. – John Maynard Kynes
Learn to let go of ideas you get stuck on, there are new ones waiting for you.