Have you seen that video with those guys playing like 50 songs using one chord progression? This is it. I V vi IV (1 5 6 4). To solo better over this chord progression I’m picking out the 3rd of each chord to target. In the key of C this chord progression would be C — G — Am — F.
The Thirds we’re aiming for are:
C Chord — E Note (Red)
G Chord — B Note (Blue)
Am Chord — C Note (Green)
F Chord — A Note (Yellow)
It seems like an exercise right now but it’s really training your ear to instinctively pick these notes in your solo. Stick through it!