I dunno if I'm really going to benefit anybody, lol, but I'll explain how I do it.
I don't have a band right now, so I do it all myself. I don't do vocals, I'm just doing the guitars/bass/drums.
I play a fast rock/metal so I'm kind of a 'mathematician' about it all. It's definitely more robotic writing this stuff than regular rock/pop stuff.
I'm a guitarist foremost...so the riff comes first. As soon as I get a good intro riff going, I try to estimate the speed (bpm) by tabbing it all on a program called GuitarPro.
I find the closest tempo that equals the original riffage and start writing the drum parts ( I use Drumsite ). There's just no way you can put down guitar tracks without the drums first. So, I write the drum parts with the tempo I calculated from the above way. Just the basic beats for now...fills/fancy stuff comes later.
Then the bass. I don't just write off the bass and throw some crappy line down assuming it won't be heard. I just bought a new Tbird bass.
I hate basslines that follow the guitar exactly. I always purposely deviate from the guitar lines. I try to follow the drums, but use the basic guitar outline. Again, I map the bassline out with the tabbing tool.
I'm sure that's probably not what you're looking for, lol, but there's my 2 cents.
