I'm not really a Satriani fan, but in a book I'm studying, I noticed that he shares his professional advice on how to practice. I don't have the book at hand right now, but essentially, he says that when you practice, whether it's a new lick, scale or riff, make sure to practice it at a tempo where you can play each note cleanly in time. Repeat that riff/lick/scale at this tempo, until you feel you can play it a bit faster, then increase the tempo by very few BPM, and repeat. At the end of the day, it doesn't matter if you've played the same thing 1000 times. If you practice slowly and increase speed only once you can play it perfectly, you'll learn to play it clearly. If you just play the same thing sloppily over and over, you'll be learning how to play it sloppily. Again, I'm not a big fan of Satriani, but his advice does help. I had a bit of trouble learning the phrases in Satriani's "Crowd Chant" (because my teacher said it's a good example of how to use the minor pentatonic scale), and after reading the advice he gave, the Arpeggio-parts seemed easier to handle.
Two other things that will help you improve and are frequently brought up on the Internet are:
1: Practice with a Metronome. This site offers one, there are tons others online, I'm pretty sure Google Play and the Apple App-store contain a few free metronomes you can download. Metronomes are so ridiculously easy to find and use, that it's almost unbelievable just how useful they are. The advantages to practicing with a Metronome are that you'll be able to track your progress when building speed, and they can help you learn to play in time (although a real drummer is better, provided he can keep a steady tempo... Drummers are usually easier to hear that the silent clicking of a Metronome). I don't know what your goals are, but if you want to play in a band, being able to play in time is very important.
Once you reach a satisfying level, you can try jamming to some backing tracks. GT has some, and YouTube has a couple of pretty cool ones too.
2: Warm-up exercises are important too. I know nothing about how muscles work, except that they let you do stuff, but I keep seeing people saying how utterly important it is to warm up before practicing or playing live. You don't need an electric guitar plugged in to do this, and if you have a tube amp (which I don't expect), you can do this while waiting for the Tubes to warm up as well. Different people have different ways of warming up, though. I know Slash used to just play what later became the intro to "Sweet Child O' Mine", and I actually find that works pretty well for me, along with a few other exercises. The general rule of thumb is that playing guitar without warming up first is like running a marathon with stretching first. You might be able to do it, but you won't be doing your best.
Keep those few things in mind and you'll at least be moving in the right direction. In the end, though, there are no secrets that help anyone improve on guitar, or any other instrument for that matter.
Have fun learning.
"Commit yourself to what you love, and things will happen."
- Mika Vandborg, Electric Guitars, "Follow Your Heart"
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Gear:
Chateau PS-10 Cherry Power-Strat
Epiphone G-400 LTD 1966 Faded Worn Cherry
Epiphone Les Paul 100 Ebony (w/ Oil City Pickups Scrapyard Dog PLUS pickups)
Epiphone ES-345 Cherry
Fender 2014 Standard Stratocaster Sunburst
Martin DX1K Acoustic
Fender Mustang II Amplifier
Jet City Amplification JCA22H Tube-head and JCA12S+ cabinet
Pedals...
- Mika Vandborg, Electric Guitars, "Follow Your Heart"
---
Gear:
Chateau PS-10 Cherry Power-Strat
Epiphone G-400 LTD 1966 Faded Worn Cherry
Epiphone Les Paul 100 Ebony (w/ Oil City Pickups Scrapyard Dog PLUS pickups)
Epiphone ES-345 Cherry
Fender 2014 Standard Stratocaster Sunburst
Martin DX1K Acoustic
Fender Mustang II Amplifier
Jet City Amplification JCA22H Tube-head and JCA12S+ cabinet
Pedals...