Everything suggested here is awesome...obviously.
Scales & Modes are the building blocks of music fundamentally, but just practicing these in a linear fashion can be boring and probably the most un-musical thing you could do!. The practice technique that kind of opened it up for me was practicing with a looper pedal after being inspired by a couple of lessons with Steve Lawson, i'd loop a couple of chords in various rhythmical patterns and this helped scale practice achieve a bit of musicality, for me at least.
The other thing is that groove is an odd one to try and teach! Its kind of like explaining hot or cold...its a feeling IMO.
Rocco Prestia once said when asked 'What is the groove' he replied
"Imagine a group of guys are walking down the street, all feeling and looking pretty cool, and one of them picks up a rock and puts it through a window......he just messed up the groove"
A bit odd, but hey, he grooves like a futhermucker, so i'm not arguing!
Good Luck!
Si
p.s.
+1 for the above post, singing is a BRILLIANT way of writing/figuring out lines!