Something that took my melodic style playing to the next level was learning scales in a specific key, and then re-learning a song in that key using just my ears.
For example, Salt Creek is typically in the key of A, played out of G position with the capo on the 2nd fret. I know the melody well enough to transpose it to a new key.
C was a good challenge, and I began to see how I can use the scales to create the melodies I wanted.
#1: Learn the scales
#2: Transpose a song you know to the key you're working on.
#3: Practice Improvisation using the scales.