So I've been experimenting with a bassline off of a guitar riff that my friend gave me, but nothing that I create is to my satisfaction.

Can anyone out there give some pointers about making a cool sounding bassline? Actually one that stands out from the guitar line is what I'm really asking

By the way the riff is rock sounding

When writing bass lines here is what I do:

I play the guitar line over and over ... and I just play the roots. It makes me more familiar with how it goes. Then I turn the CD player (computer) off and start experimenting with the progression. Even better for me is to play the line over and over on a guitar (!) so I get in my guitar players head a little.

If the progression is D - A - G - A - D (or whatever) in 4/4 then I start moving beats around... I may just be playing roots and thirds or fifths... but I get my hands moving....

eventually... a bass line comes out of it. Play what is in your head... not what is on the paper/CD/Mp3.

Works for me. Others hate it. Oh well.

This has been said a million times, and for good reason: it works: Sing a line. Once you have the guitar melody or chord progression in your head, start singing or humming a bass line to it. Then, when you have something you like, record it, and then transcribe it to your bass. This is a good way to break out of muscle-memory patterns so that your voice dictates the sound on your bass, vs your fingers determining what's played.