Historians believe that Music was born out of speech and in the beginning there was singing. And indeed, singing what you play is an obligatory exercise when learning to improvise. For instance, George Benson sings and plays in perfect unison (this is also his trademark). Listen to Keith Jarrett’s indistinct hum (he’s not the only one, you may see in live performances players singing while improvising but the over-all sound covers their hum)! Is it a reminiscence of his improvising practice or does he want to add more phrasing to his playing?
Another approach would be play on your instrument while you listen to your favorite singers and imitate their phrasing. Stylish singers, like Al Jarreau, Ray Charles and Billie Holiday would be preferable. Take the recording of your improvisation that you think it's the most "lyrical" of all. Could you write words for it?
Also: don’t forget that your solo like a story, it's supposed to have a beginning, an end and dramatic peaks in-between.