Bass groove resources and techniques

sharke
One technique I sometimes use to come up with bass lines (doesn't work in every case) is to write the chords of the song as sustained notes in the piano roll, then enable Sonar's arpeggiator and set it to something like 8th or 16th notes with whichever arpeggiator mode sounds closest to the kind of thing I want. Then, I bounce the MIDI clip, which will replace your chord MIDI clip with the arpeggiated notes. This is just a foundation of raw material to work from. Then go into the piano roll and set about playing with these notes - deleting some, moving others, adding new ones, lengthening or shortening some, maybe change the rhythm to triplets or dotted notes here and there. It's just a matter of trial and error, working measure by measure and trying stuff and playing it back until something good emerges. It's quite a brute force way of working and also random to some extent, but sometimes you end up with something which is really good and which you never would have come up with any other way. 

electrodome1
Sometimes I think the best thing to do is to produce the entire project, then add the bass at the very end.