It is fucking difficult, when I was a child I learned solfa, music theory or however it is said. I could sing basic pentagrams in real time while reading... Now, 25 years after, my brain has some seconds of latency and I sing it after processing... but very badly. I should change my brain interface or something.
Hahaha I hear ya, dude There is no masterplan for it..just training, training, training each day. After I had sightread some complete "Realbook of Jazz", I actually was able to read and recognize whole typical cliches, instead of single notes. If you got a good hearing (harmonywise) it´s pretty useful, as well. Then you "guess" some of this phrases easily.