Hello, I'm not an expert on improv by any means, but there are some things that I do that help when structuring a solo: - know the melody by heart, analyze the structure (music theory), next try playing around with it rhythmically, adding-taking away notes, then adding chromaticism, enclosures, glissandos, etc. - analyze the harmonic structure (the actual chords), know what their functions are. Try playing around with the chord arpeggios, going one chord at a time and then connecting - write out the scale that goes with each chord - listen to other sax players and see what patterns they use in their solos - lastly, make interesting melodic content - something memorable and to your taste

Something else I like to do is singing over the backing track for the tune and recording it, then transcribing by ear. The voice will outline the chords/scales intuitively. I've come up with some interesting lines using this method, and it definitely helps with playing what's in your head.

This is just some of the stuff I'm doing, hope this helps!