DISTORTION-
The best way to achieve distortion is to get a distortion pedal and play around with that but, for those of you that don't have distortion pedals, here are some easy ways of achieving this loud, noisy, and sometimes ear-ripping art.

-Turn your guitar and/or amp up to a high volume and simply get close to your guitar.  This will give you a sort of siren distortion.  (The speed of the feedback depends on how high the volume is.) 
From that, you can achieve different sounds by:

-Put you hand on the strings and then releasing them

-Hitting the back of your guitars neck.  This gives you a low grumbling noise and will lead to a screeching noise.  Kinda like the intro to Breed and Negative Creep.  You can also bend the back of the neck but there is a chance of the neck cracking or snapping.

-If you pick the strings behind the nut, you get a high distortion which is pretty cool.

-If you have a Fender Strat, you can change the pitch of the distortion by moving the 5-way switch.  You'll have to find out how the distortion changes on your individual Strat.

-You can hit a high note on the high e string and hold it, you may get a high distortion.

-If you are close enough and have a high enough volume you can achieve distortion when you release a power chord.

-If you have distortion, you can try to bend certain frets on certain strings to get a 'wah wah' sound.

If you hit the 3rd, 12nd, or 15th fret with your fingers lightly on them, you can sometimes get distortion.

(--You can always find new ways, so if you do you can e-mail me--)