Writing your own basslines..?

Any tips for this?

I get an idea, or I sing an idea and try to replicate it, but its often usually small like only one bar long and becomes a bit too repetitive.

Is it better to start with guitar chords and sing to them, then build a bassline
from that?

For me, if I have an idea for a riff or lyric, it's a matter of building the rest of the song around that part, trying to create music that sounds like a natural extension of that riff or lyric. Like for example, if you look at something like Enter Sandman, the main riff is integrated throughout the entire song; every verse and chorus riff sounds like a natural extension of that main, chugging riff.

Unfortunately that's about as technical as I can get. I've never studied music theory or anything like that, so most of the original stuff I do comes from instinct, drawing on my wide knowledge of various musical styles. Like, in my first band my buddy had an idea for a song but couldn't exactly put his finger on how he wanted to play it. He said musically he wanted something along the lines of “Cut You In” by Jerry Cantrell. So we basically took that song and mixed the chords up a bit, played them in a different order and to a different rhythm, and took what he had afterward and just fine-tuned it until it sounded like something completely original. It turned out to be one of our best songs – we took his incomplete idea, added some Cantrell to it and built it up from there.

Music is a cannibalistic medium. Every artists borrows – nay, flat-out steals – from others. The trick is to add your own stamp to it.

My guitarist emails me tracks he's put together on his computer and I just listen to them and the bassline starts forming in my head, then I start to sing the bassline, you know, dum dum de dum, that type of thing and start playing along to that, then when I'm satisfied I'll write it down in tab form. To avoid repetition just put som subtle changes in like octaving a certain note or changing to eighth notes or even leaving a space, the notes you don't play are just as important as the ones you do

Ok some progress, I wrote this song about a year ago as a tribute to a friend who killed himself. Not the most cheerful subject, but I wanted to do it in memory to him.
I could never really get it going on guitar, I just couldn't find the feel.

I put on a drum beat like suggested and played around on my bass and kind of sang/hummed, I came up with a prog of 6 5 4 1 5 which in C would be Am G F C G (but I put it in A)

It works for the song but as always I need to tweak things, its good to have something working though.

I sit on the piano and write first on sheet music then i sit down on the guitar and write down the rythm then i pick up the bass and write down some lines for teh songs or if i just happen to feel electric or jumpy or like theres a ggroove stuck in my head i try to write it down on paper ad start from there

I haven't created anything original in over 20 years. When I played with a band, and had to come up with my own stuff or write pieces I struggled.

My bass lines always came from the drummer. I tried to match the drum beats with the guitar.

I can't sing, so I was never any good at creating bass lines around vocals.

After writing this, I realize I would never hire me as a bass player. HAH