I'm no Steve Vai, but over the years I have struggled over this and think I found something that works for me, and it seems to align with what Steve is saying.
1) Relaxed does not mean distracted. In the same way that meditation _forces_ you to relax your mind while focusing, you should consciously try to feel and untie any physical tension that affects your playing. That means it's an exercise itself.
2) When you practice the technical stuff, you should do it slow to be able to focus on it, and not put more in your mouth than what you can actually chew.
3) When you practice the technical stuff, you should do it slow for another very good reason : your muscle will learn it better this way. In my experience practicing slowly enabled me to play much faster and more importantly more fluidly that I would have if I had targeted a certain speed and practiced it more sloppily at say 80% of the target speed.
If you have a high target speed then you might want to use a secondary step where you try to play it as fast as you can and analyze how it breaks down _then_ go back to sow mode to work on that. Lots of players and teachers insist on tedious incremental tempos, but most of the time it's too boring for me.
That takes time, but it's a labour of love. I found the reward for this kind of practice to be well worth it, and enjoy the process, not just the result (that last bit is the pearl of wisdom that eluded me for years).
4) You practice to play music. Are you practicing something that you have no musical use for? Get rid of it or turn it into music. Music will speak to you and help the whole process. (this does not apply to warmup)
5) practice melodies and train your ears. The muscle is where the tires hit the road, but your sense of music is what steers the wheel (and plans the trip, sets the GPS up, you get the idea). Each time you connect your inner ear with your fingers it will be a bliss. Each time you don't will be an opportunity to learn something.
(Jeries, the volume of practice is of course a factor, but practicing incorrectly in volume will mainly increase frustration ^^)
Hope that helps.
Last edited by Pif on Mon Aug 26, 2013 3:45 am, edited 1 time in total.