Instead of always landing on the root notes, or using trial and error to figure out more interesting sounds, is there some more reliable or methodical way of finding the "right" notes? I have difficulty figuring out where to start and end on a scale form when soloing. Some guitarists sound awesome making runs that don't conform to the standard modal patterns. I would like to be able to do that so I don't get trapped using the same type of patterns and mechanics.
Furthermore, I have some trouble finding the right key to solo in. For instance, if I come up with a rhythm that centers around a D power chord, then soloing in DM/Bm or Dm doesn't always sound right or sounds bland. Then I have to record those chords in sequence, reference a key chart, and see what key sounds best. It's difficult to understand since all of the notes in the chords I could be playing are within the D major scale, and using the modes of DM still don't sound right. Then I try another relative key or something and then I find it. That, or I might find the right key but only the pentatonic notes seem to work.
Maybe I'm just thinking of it the wrong way. I don't know but I sure could use some help and a simple perspective on how it works.