CO-SIGNED. I haaaaaaaaaaaaaaaate all the ideas that arrive at work, and you get all of the words and it's all BRILLIANT, and then you get to your computer and...nope. Words gone. It sucks.

<3 you'll crack it one day! And I find it sometimes worth just writing down something that you think is crap, leaving it for a little while, and then coming back and polishing. For what it's worth, anyway!

I have a very similar problem, which is why I keep a notebook and pen around my person at all times. Looking at a blank page can be the most challenging part; you allot time for your muse to run free and, being fickle, it gives you nothing. Maybe try coaxing something out by gardening/cleaning/folding laundry - something where you're occupied with a chore that leaves your mind free to roam. Simulating work, I guess. You might find that the ideas start edging into view in the corner of your thoughts, giving you a chance to snag it and write it down since you're not actually at work.

And with the 'worth writing' bit, I second Ashen's vote for just writing it. Even if you end up tossing it out completely, at least you're getting your muse revved up and words on paper.

...yeah, I don't know if any of this is actually helpful, most of the time I just keyboard smash until my creative side gets disgusted and jumps into action to save the story.

Thirding the 'don't get it right, get it written'. Get words out, editing can happen later :)

*attempts to help*

I find it helps not just to write down notes there and then, but to write something down that paints that idea for you, an exchange of dialogue or turn of phrase that's what made you want to write it and will (hopefully!) bring the imagery/sounds back into your head when you come back to it.

Maybe don't sit down staring at a blank page determind to write a story? Maybe just type out your scraps and then a few more scraps, a funny line, a joke, a quote, something that catches your interest like rope (rope seems to be on everyone's minds at the moment, no idea why *grins*) and see where it takes you?

Or start off by writing something else. Sometimes I did a few fills for comment_fic prompts that got me going and then dove into something bigger :)

OMG THIIISSSSS.

This happens to me all the darn time. I get the best ideas at work. They literally write themselves in my brain... just pages and pages and pages of text, the most beautiful prose, the most insightful analogies, the subtle and stunning meaning. It's all there.

But I can't write at work. I can't even stop to jot down a few key things in a notebook. So I file those pages away until I get home. Then it's dinner, dishes, kids to bed, and I sit because I can write. I finally have time to write. And then it's gone. Just... vanished. Pages and pages erased blank.

Write something. Anything. The words might come back. Or maybe you'll stumble across something better. (and I really really need to take my own advice here)