I guess you're all wondering what it is I've learned. Giant Steps!! That's it, I can play and solo over Coltrane's tune Giant Steps. I'll post the video soon.
Here's a few tips: practice playing the changes and soloing way under tempo, then gradually increase your speed. Play slowly will force you think about what you're playing, and have to make better melodic phrases (not just play a bunch of notes quickly). Also, learn what scales go over what chords, i. e. Lydian over major7, Dorian over minor7. And, this one is very important learn how outline 2-5-1 progressions.