Good question.
Split it up. Focus on areas with the degree of specificity that suits you.
Use the metronome.
My routine -- guys, please critique this and make any comments.
AM:
Strumming/RH Rhythm
Chromatics
Left hand legato exercise
Improvisation ( I solo over my own recordings)
Afternoon:
Tapping
Scales
Arpeggios
Evening:
Reading
Riffs
Effects/goofing off
Sweep picking
I'm always looking to improve. If you have any comments on the above, lets hear them.
It's a good idea to stick to a routine until you get to a certain goal, then switch it up.
For improv, you'll get your own sound if you record your own riffs and then record your own solos. Gilmour does multiple take/composite solos, and his solos always sound great.
Recording makes you try really hard to play it right, too.
You can also schedule in a little leeway for playing with your wammy bar, wah wah, sliding, or whatever.