Hey, ive been playing guitar about four years now, and i always practice a lot, but i seems that i never improve at my playing, could you tell me what to try? i know the scales and some songs, and its very frustating that i never improve my guitar playing, this is some stuff that i been playing lately, if you could tell me how and what to improve i would be very gratefull.
https://soundcloud.com/pablo-manuel-2/d ... tar-tryout

It's good that you've learned some scales and songs, that's a decent foundation. It sounds like you've never practiced to a metronome, and haven't been paying attention to how your notes sound. You can work on both of these things using http://metronomeonline.com/ if you don't have a metronome - start at 100 or so and play one note per click, paying attention to the tonal quality of each note. It needs to sound flawless. Move up to playing 2 notes per click, then 3, then 4, then 6. When you comfortably play 6 equal notes per click, move up to the next speed on the metronome. You can practice tremolo picking, arpeggios, or scale runs with this method and see rapid results.
When you're playing along to songs you've learned I also suggest using a metronome, even if you're playing along to a recording of the song. I found this video extremely helpful toward improving my own playing: http://www.youtube.com/watch?v=eMhqAGDeY9A

being really creative and writing lots of your own riffs is what really makes someone good at death metal - in my mind - songs live and die by creativity and riffs

^That said, it can also result in you simply writing riffs around the limitations of your own ability, meaning you never improve much. Not that it's a bad thing if that's all you want to do, but the OP did mention wanting to improve.

guitartheist pretty much said all there is to be said about the metronome and timing and practice methods. Here's some tips for death metal specific techniques.

Pinch harmonics. Get them super-clean and bend the fuck out of them, this is what makes them aggressive. Learn to do both a rapid vibrato and a slow bend(on pinch harmonics, I mean).

Chugging. Make this heavy, really fucking heavy. Try to hit 2 or even 3 strings if possible, but with good technique even chugging one string should sound heavy. One way to do this is to move your palm a little bit further up from the bridge, but not til you bend the note sharp. Just to get a bit more of a percussive and thick effect.

Pick very fucking hard. Don't worry about wearing picks down or breaking your strings. Just pick hard, and whenever you play big chords or power chords, hit every string involved to get that juiciness out of the chords. It may take practice at higher speeds, even to this day I have some issues with that, but that's what the metronome is for.

EDIT: Just listened to the soundcloud link. Here's another tip: Learn songs that are good for your technique, not just fun songs. I've been playing for about four years as well, slightly less, but the early days of learning Venom and Celtic Frost songs didn't help much other than helping me have some fun. Good death metal songs to learn in order to build technique are stuff from bands like Carcass, Vader and Bolt Thrower. IMO this is a good balance of both fun and building skill.

Thank you all, i will practice with the metronome (never done that) @guitartheist @NecropsY and @somefella all of your advices are gratefull and they seem to be very helpfull, i owe you a beer.

No worries, happy to share. In the words of Wino, if it ain't heavy it ain't shit!

No. This is a bad idea, because:
- When done un-palm muted the strings go out of tune, giving a shitty bend feeling when you do it "very fucking hard"
- In high gain there is little difference between "playing hard" and "playing very hard".
- Due to this making little difference, it is pointless waste of energy, because if you want to play death metal, you want to be all over "efficency", and stuff like not pressing strings down to shit on fretboard, not beating the shit out of your strings, economic movements etc. Why do you need economic movements, you might ask? To play fast. It will take little to no energy to tremolo pick at 200 bpm, shred, and stuff if you do it correctly.
There is one exception, like I said, you can beat the shit out of palm mutes because unless you try your best you wont get them out of tune and when palm muting, and it gives it a bit more punch.

Regarding death metal playing tips, like in point 3, efficency. Do stuff very slow at the beginning, and focus on getting it right and with no strain. Practice for example one scale, give yourself a goal to do it flawless 10 times back and forth at a set metronome tempo, then kick it up by one bpm until you are having trouble doing the 10 flawless runs, then put the metronome down 10 bpm and play, carefully watching your picking, hand movement, and focus on making it right, noiseless and economic. We dont want to beat our strings to shit, we want to use just enough force to make it sound coherent but not too much, so we can effortlessly sweep through the strings at insane speeds.

If your unmuted strings go out of tune because you whack them, you're using the wrong gauge or very shitty strings/guitar.

Second point, that means you're using too much gain. If there isn't a difference in sound when the impact of your right hand differs, that is. You might as well program a midi and put samples on it.

EDIT: By the way, sweeping, shredding and 200bpm tremolo picking aren't death metal techniques, but shred guitar techniques. They might be applied in tech death but that's it as far as their death metalness goes, unless all you listen to is Brain Drill. Death metal is about attitude, heaviness and groove. And playing hard isn't inefficient unless you're doing it with wrong technique. The best death metal guitarists abuse the fuck out of their strings, its YouTube cover artists who do everything squeaky clean and perfect.

I agree with the other gentleman here... Just practice picking a fuckload. Even just one string. Start out slow, and just gradually increase speed... do some simple scale runs (even just chromatic noodling). You'll get it.

Though, I don't know how much my advice is worth, because I'm still sloppy as hell. hahahaha

Thank you all very much.

I dont know somafella, maybe we listen to different kinds of death metal, but 200bpm+ tremolo picking is found often in non-tech death metal. About every OSDM solo is shredded, and some use sweep picking, but rarely. If you want to have "all" the fun including the solos, you might consider learning how to shred. Plus, tech death isn't all sweeps, it shows you didn't listen to much tech death or have any clue. Actually, the best death metal guitarists play pretty economically (I consider Jon Levasseur one of them, check Serial Messiah playthrough an live videos, you can notice he picks with just the right force and doesnt beat his guitar to shit).

Regarding the strings, I use just right gauges, the lowest string being at 18-ish lbs. I can get it out of tune easily beating the shit out of it. If you cant, maybe your "very fucking hard" is not even "very hard" at all. Unless you play 13-62's in standard, then I can see why you are having trouble, but that is beyond stupid.

Not picking like a pussy doesn't mean being uneconomical. You can't say something is wrong by trying to forcefully link a worst-case consequence of it's extreme, then you're just arguing for the sake of it. It's still better to use more force than less when riffing, especially for death metal. But hell, that's true for every genre imaginable, don't tickle your strings.

I don't beat the crap out of my strings but I also only downtune to D standard. Speed and precision is way more important that playing hard, just watch Cannibal Corpse when they play live. Check their picking hands and you'll see.

Just because it doesn't look like their picking hands are flapping around doesn't mean they're not picking hard. Pat O'Brien regularly has tuning issues in studio because he hits his strings TOO hard(which is not what I'm advocating). The problem I see with most beginners is that they're hitting too softly, hence the advice.

EDIT: Also, you're assuming that picking hard makes you unprecise or slow. I'm simply saying that it's good to dig in and hit it when riffing.

Forgot to mention that I downpick pretty much everything!

Thank all of you, i started practicing with a tremolo, and something i noticed is, that when you dont hit hard the sound is more weak, but it may be my gear (i have a squier guitar and a Behringer 15 watt amp) i have to admit, that playing along the tremolo is harded that i thought, i try to pick the both ways and about soloing, im not good at that ethier.