#1
ive been playing about 7 months now and i heard you can write riffs with powerchords but im kinda stuck on how you actually get it to sound good
#3
To answer your question in the easiest way possible, learn the major and minor scale pattern. Then, just play around with power chords so that they follow the scale. Experiment and try them in different positions. The easiest way is probably to just play 4 power chords in a row and then improvise from there or whatever.
#4
Well, here's the thing. Powerchords are the basis for most riffs. BUT not the whole of most good riffs. For example, most bands use powerchords to anchor the riff but single notes to fly the riff. Wat I mean is, yes, powerchords are good for stressin the important parts but use some other notes/chord combos, as well. Consider that an F#m or Fsus4 can really be played with two notes. (It doesn't really need a fifth to be the chord. Yes, it isn't a full chord, but so wat? It works well with powerchords.)

Consider the two riffs below:


E-------------------------------|
B-------------------------------|
G-------------------------------|
D-------------------------------|
A-2-2-5p0-2p0--------------|
E-0-0-------------3p0-2~~-|
E5 (N.C.) Eminor

AND

PM-----------------|
E----------------------|
B----------------------|
G----------------------|
D----------------------|
A-2-2-2-2-7-7-2-2-|
E-0-0-4-4-5-5-2-2-|
E5 G#m A5 F#sus4

See wat I'm talkin bout? The 1st example uses single notes, rooted by powerchords, to drive the rhythm. The 2nd uses powerchords and half chords to grind the rhythm. Be creative, there are hundreds of ways to use the notes and chords to create original riffs. Don't become a powerchord *****. Use everythin and anythin. Good luck and peace, man.
#5
Powerchords works, but its pretty boring because its so........... used.

Try to experiment with chords instead. The Fall of Troy experiments a lot with chords, try them out for inspiration
#6
POwerchords are very useful, but try not to use them all the time, e.g.

The worm by Audioslave

e|-----------------------------------------------------------------------------------------------|
B|--------------------------------3-2---------------------------------------4-2---------------|
G|-2--4----2-4-4-2-4-4-2-4--------4-2---2--4----2-4-4-2-4-4-2-4--------4----------|
D|-2--4---------------------------------------2--4--------------------------------------------|
A|-0--2---------------------------------------0--2--------------------------------------------|

First thing that came in my head lol

Edit: Sorry it's ****ed up, but just search for the tab or listen to it you'll see what I mean
#7
Just mix it up a bit dude, mess around with your axe and eventually you'll get some cool sounding ****. Any particular metal your looking to play?