Here's a technique I have found to be quite useful in my repertoire because it allows me to fire off fast technical passages without having to be warmed up.
It consists of using a combination of unassisted hammer-ons, slides and tapping to execute relatively quick licks and runs. While "shredding" tends to traditionally require all of your fingers working rapidly to produce a steady flow of notes, this technique allows you to use only a couple of fingers at a time.
FIGURE A (below) utilizes the E natural minor scale (E Aolean), and it is grouped in 16th notes (Or as I like to think of it, in "fours").
It's very important to note the specific fingering that should be used when playing this. You might also benefit from using a dampener, which can be something as simple as a hair scrunchie that is tied around the neck of your guitar where the nut sits, just to keep the rest of the strings from generating unwanted noise as you are hammering on, tapping and sliding throughout this lick.
FIGURE B starts off with an unassisted hammer-on and ends with one as well. Another thing to make sure while practicing this is to maintain the same volume of attack between every note, whether it is an unassisted hammer-on, a slide or a tapped note.
Finally, the last example is FIGURE A and B combined. They flow into each other to create one long lick. Remember to check out the video below, too!
Cyamak Ashtiani is an award-winning rock/pop guitarist and songwriter who has written, toured and recorded with a multitude of major and indie recording artists. Recently, he has toured with Rockstar: Supernova's Lukas Rossi and country/rap artist Mikel Knight. You can catch his new project with former Dry Cell frontman Jeff Gutt at ShadesOfTheVillain.com and his clothing line at 1251Clothing.com, of which he is a cofounder.