Here's a pretty straightforward solo. To play the changes I simply use
chords tones and chord shapes.
Over the D chord, notice the passing tone (the minor 3rd, F) and the classic pedal steel lick in bar #2.
Over G, we target the B note, the major 3rd and follow the chord's shape.
Then we have a nice open strings line leading to the A chord and again we target the majord 3rd of the chord and use the chord's shape.
And finnaly, a classic sounding lick over the D chord to end the solo !