Even the greats get Writer's Block. But when you're Theodore Sturgeon, you can get some advice directly from Robert A. Heinlein.
At the 1962 Worldcon, Sturgeon explained:
I went into a horrible dry spell one time. It was a desperate dry spell and an awful lot depended on me getting writing again. Finally, I wrote to Bob Heinlein. I told him my troubles; that I couldn't write-perhaps it was that I had no ideas in my head that would strike a story. By return airmail — I don't know how he did it — I got back 26 story ideas.
It only took a couple days for Heinlein to respond.
And now, the awesome website Letters of Note has the entire Heinlein letter up. It's classic Heinlein – irreverent and erudite at the same time. And you can see the way he thinks through stories, not just as ideas, but as ideas that could go in any number of ways or that will appeal to specific publishers.
My favorite story idea from Heinlein's letter is probably, "June 28-The new bull calf looks better all the time. Met a leprechaun today. Nice little guy. I'm going to have to drain the south forty." But you should read the entire letter and find your own.
But the best thing about the whole story is just how gosh darn sweet Heinlein is. As Sturgeon said, "This mechanical, chrome-plated Heinlein has a great deal of heart. I had told him my writing troubles, but I hadn't told him of any other troubles; however, clipped to the stack of story ideas was a check for a hundred dollars with a little scribbled note, 'I have a suspicion your credit is bent.'"