I think you are right not to want to turn on a metronome an just "crank it out." I think that's not very useful.
When I work on technique, it's sort of meditative; I decide on one thing to focus on and they pay very careful attention to it. So maybe doing scales I decide I need to work on relaxing the finger as soon as possible (not lifting it from the key, just releasing all the downward force I used to strike the key) so I play the scales paying attention to the sensations of downward force in my fingers and to the upward force of the key's rebound when I relax the finger. I keep doing the scale while I pay attention as carefully as possible to the sensations and listen to the sounds I'm making and try to get a feedback loop between sounds I like and comfortable sensations in the fingers, wrist, arm, etc.
Working on speed and evenness for scales I do all the rhythm things that Josh recommends; long-short, short long, short-short-long, up to six or seven fast notes, then a long one, and I do those starting on each successive note until the pattern recurs. That way I train the reflexes to go fast, but stop and relax completely between each burst. Because the bursts are short; it's easy to focus on exactly what's going right and wrong during each little burst of speed, evenness of timing and volume, hand position, alignment of the active fingers with the keys, etc, so for me, anyway, it's easier to pick out where a finger is late or where exactly the two hands aren't precisely in synch than if I just run through all the scales round the circle of fifths at full speed.
The thing I like about technical exercises is that I can focus completely on whatever detail of the mechanics, sensation, sound, relaxation, without having to think about the complicated details of an actual piece. I wouldn't spend too big a fraction of time practice time doing just technique though - out of 3-4 hours a day total I spend maybe 40 minutes on different technical things.