I do pretty much the samething you do, but I only do it until I feel like moving on, usually in the range of 30 minutes. Maybe it's the fact that I have already gotten most of the techniques done pat, and all I need to do is go through a refresher.

(everyday) The first thing I do when I practice is go through finger warm-up exercises to get the blood flowing. Once I feel my fingers are warmed up, I go onto scales.

Always do all my scales with the same root, and change the root daily. I think of the root, play it to make sure I'm on. Then mentally think of the scale in my head, ascending and descending. Then I play it to make sure I was right. If I found I was alittle off on intonation, I spend alittle more time practicing singing the scale. I've been doing it for so long I usually don't mess up, but it happens sometimes. I don't do every scale this way, just the common ones like maj, min, HM, MM, blues, sym.. I will also go through singing chords, which is done by singing them broken. Once I have sung all the chords broken. Using the same root as the scale practice, I play through the chords of that harmonic minor scale (because it contains all the triads) and major scale. Then I pull out the metronome and work on my speed and timing with each scale. Which doesn't take long because I work with a comfortable speed daily. Once a speed becomes too comfortable, I move the tempo up to where I can play it but it alittle faster.

(as much as I can) Then I'll go through songs that I have written or know, and those cover most of the techniques. I try do go through as much as I can. Then pull out a drum track and jam around with it, write a song, or do whatever I feel like doing. Sometimes I don't touch the guitar again, or I play for a couple of hours more.