Learn your scales. If you're starting out, start with the pentatonic minor scale. There are 5 "box pattern" positions to learn. learn them all. Then learn the natural minor scale in all positions. And learn to alternate pick them. There are also 5 "box pattern" positions for this too. There's a 3 note per string variation of this. If you are a total beginner, ignore this for now, but keep this in mind so you can revisit this when you get more advanced. As you explore these scales, you'll start discovering how these apply to metal on your own. I know I just threw some terms at you. Take these terms and google for them. There's tons of internet resources to help you learn these.

There's a ton more info , but this is a good start. I know this is quite a chunk of stuff to learn, but just about everyone had to learn it. You can too, and in time as you apply yourself, you'll be the one offering the advice! :-)

It's not in just metal, dude, lots of styles demand scale knowlege. Just learn a bunch of minor scales and you'll be set for metal playing; practice them untill you can play them with your eyes closed and then you can make up a riff or shred a solo in no time. (not without practice of course)

Wow, why did someone give me a negative web credit? I thought I gave good advice.

I know scales aren't just for metal, but Guitarplayer22's question was directed specifically for metal, and that's why I answered the way I did.

They probably did it on accident. I bumped you up one because I liked your response.

it seems like all scales sound really stupid and happy when i play them. Why?

the great thing about metal is that you can play notes that are totally off key and it can sound really wicked (if you know what you're doing that is, lol)

the genre often uses more exotic and darker sounding scales, particularly the natural minor scale

these scales are full of tension and usually contain notes that really "define" the sound of the scale, harmonic minor being a great example of that. (the flattened 6th) other scales may include the phrygian scale, lydian scale, and even spanish gypsy and byzantine scale.

improvisation can prove to be a bit more challenging with these scales.. so learning to improvise with the major scale and/or minor pentatonic is ideal prior to trying your hand at some of the more exotic scales

improvisation can be very difficult at first with any scale, but the key is to learn to play the scale not like a scale (ironically), then putting together more melodic patterns.. eventually it will come almost naturally with a ton of patience and perseverance

always take things slowly at first, only speeding up once you can play it in your sleep. and remember its all about expressing yourself, let your solos breath, and don't rush anything

You know another very simple trick for metal improvising is simply to play around with pentatonic scales without making it sound too 'bluesy'.

ALSO...

-Important balance for lead playing =do more listening to other muscos than playing

-ALWAYS practice to a metronome

-Speed scales up as your feel comfortable -Push yourself but never play anything faster than you can play it clean

For some great ideas & or inspiration go to guitarshredshow.com -there are lessons on modes and loads of cool licks -if nothing else its quite entertaining

Also... When practicing soloing... I find it best to play over a backing track. This way you can tell when you are off and not staying with the key. It also helps you discover which scales can be played or best used over different arrangements.

I certainly agree with using a metronome if you are replicating pre-defined solo's exactly and need to built up to a certain tempo in order to play along at the pace of the recorded song or band.

Record yourself often to see if you are actually producing the sounds that your brain is telling you that you are playing. You'd be suprised at how much stuff happens that you didn't hear at first. You will also notice that you will sometimes wonder why you don't hear stuff that you are sure you played.