Voicings on inversions
From Gypsy Jazz Guitar Wiki
This is the kind of voicings that you can do when you don't want to take too many risks: play a melody on top of chord inversions mixed with diminished chords. To benefit from this technique, the only necessary thing is that the chord lasts long enough to play different inversions. Of course, you will have to learn all inversions (that's 8 of a kind if they are played on 4 contiguous strings on the high and central strings).
Let's start with Gm6, its 8 inversions are the following. Four on the high strings:
And four on the central strings:
Now let's introduce the diminished chords, we get the two following charts:
And on the four central strings:
Just with these schemas, it will be possible to improvise melodies on the highest E string without ever being out of tune.
If you get the principle, you can also try on many other kinds of 4-note chords such as 7, m7, 7M, m6, m7M and half-diminished. Do not forget that Gm6 and Em7/5b (half-dimnished E) are equivalent since they're made of the same notes, and in the world of voicings, that inversion sounds good.