practice and just if you have any talent youll come up with something after a while
just let it flow, play some chords, i dont konw, you have to know something about the guitar first
yeh, its just am atter of time, i have amde up a few pretty good riffs, but thats only a few outta loads of tries, and moslty confined of power chords, with little extras and stuff, jsut play around, start of with some 4 chord combinations and progress from that
PSN: Noverion
the only way to go about it is to just do it. every time you play, try to come up with something that interests you. even if it's not that impressive, play it till you know how it sounds and you can play it perfectly.

getting better at writing requires that you know how to get any sound you may need for the song out of the guitar. this may seem like a tedious and neverending process, but think of it this way: are you even able to picture yourself not knowing a single thing about playing guitar? probably not. your very basic guitar knowledge is SO ingrained that you may as well have always known it.

the longer you play, and the more constantly you write, the more ingrained, "taken-for-granted" songwriting ability you will have. You will then be able to focus on other aspects of the song besides composition, such as dynamics, feel, etc, etc... without having to think too much about what your fingers are doing.
Learn your chords and scales. That right there is the best way to do it. Then, just screw around. Try writing some lyrics, then putting 3 or 4 simple chords down to play along with them while singing the lyrics.

Learn your chord scales, so you know how to write catchy riffs and so you know what chord progressions sound good together. C, F, and G sound good together, because they are the first, fourth, and fifth. You don't know what that means? You should learn the chord scales. That's what I use to write chord progressions to songs, and it really helps.

Okay, so you have the notes of the scale. Let's use the key of C, okay? The notes for the key of C are:


The chord scale pattern for a major key is:

Major minor minor Major Major minor diminished

So, you'd add those endings to the notes of the major scale for that key:

C Dm Em F G Am Bdim

See what I mean? You take the major key chord scale pattern, and put it on the ends of the names of the notes for the major scale. This will give you immediate access to chords that will sound good for that key.

A commonly used pattern in popular music is the I, IV, V pattern. That means you take your first chord (C), your fourth chord (F), and your fifth chord (G), and play something with them. It sounds really catchy. There are others, but I'll let you discover your own.

I'll say it again...learn your scales! The Major and Minor scales will give you almost unprecidented access to writing riffs.
im writing my own stuff now, and i think and have heard from other people that theory lessons will just expand your knowledge of guitar and you will be playing thingsyou have never even thought of b4 so thats what im doing starting next week, and i look forward to it. I know the guy who will be teaching me and hes just amazing when in comes to composition so im just rambling about how i cant wait to take the lessons it seems.... but you should look into it too make sure you say theory lessons and not guitar lessons