This is such an AWESOME question, Craig... and the diversity of answers is amazing... A man of many words said a lot in just a few:
bapu
For me it all starts with words.
Don't need SONAR for that.
I agree! Often I start outside of the studio/DAW land... a lot of what I do stems from focusing on an issue... sometimes a podcast dealing with a particular climate situation or solar/technology thing, a twitter link or study or ... I'll be driving and listening to some sciency thing and finally pull off the road, wip out Evernote, and start writing, REAL TIME, while listening. Hook lines, many are there in what people say... and I've been swept away into a writing frinzy more times than I can count...listening to an amazing human discussing something that I feel is crucial to understand.
I have 20 or so themes active at any time. Actually, this number continues to grow... As a vocalist I'll then reflect on a subject matter and how I emotionally react to an issue and bring up some rhythmic/arp/multi package(s) that seem to fit the picture I'm feeling, and then just vamp... often with words on a separate monitor, Often with a drum underpinning that I just select from the endless pile I have, always with headphones, mic on and... away I go. I may do this with a variety of starting points, and may vamp on several possibilities before I start to flush things out for a word package... Of course, I sometimes just fire up a new instrument or "package", like the Guru's new Kreaturesque package... and just start there, with absolutely NO idea of what I'm gonna do... That is just as fun and the spontaneous combustion which results is often a reward in itself... When Airwave and Skippy came out with their O2 masterpiece I spent ALL NIGHT writing... totally extemporaneousa but powerful songs, singing/playing real time, not knowing where it would go next, moved by the multi itself... a dozen songs, several very good, in an all night "holy SHEEEET" session... I love a number of those moments, like "are we a virus" which TOTALLY flowed from the power of others gifted into my hands and daw...
My mood or state of mind generally moves me in a direction... whether emo, country, new age, rock, orchestral, angry screaching or plantively calling out or whatever... I'm never in a box...well, I AM in the box of saying something that needs sayingt... Indeed, sometimes I'll just fire up a vst...an OT guitar, an Albion patch, or guru Omnisphere multi... and let the muse take hold. Often with NO predetermined melody... even though I feel melody and hooks are key to a song that communicates.
I go thru phases... on my last camping trip, armed with just my acoustic guitar and a smart phone, I vamped dozens of ideas I would NEVER have come to in my studio setting...words, riffs, rhythmic foundations... I was like, "WTF!!! where'd this come from???" Being able to live capture these days is HUGE.... I remember the day when I had to concoct my own system to remember an idea, before the digital age. We are SOOOOOO lucky at this moment in time to have the tools we have.
Like my gardens, I feel songwriting is an artistic adventure and I try to avoid rules for what first flows. Sure, after I come up with something that excites or brings tears to my spirit, I'll do the tear down, edits, and redos/harmonies/overlays... the boring but necessary piano roll tweaks...
But mostly, it's art... and it is soooo amazing to be able to wield someone like Airwave's art as a foundation for my own unique feelings and perspectives...It's like being IN a band without dealing with the challenges of BEING in A BAND! Every patch library is a creation lovingly put together by another human... and THAT sound, which I WOULD NEVER find on my own, rocks me into directions I NEVER anticipated...
I own ALL the costly tools but rarely use them, due to lack of time and general overload. I don't redo as often as I should. Indeed, part of why I'm relocating up north is to have way more time to devote to honing my often crude emotional appeals... Excited to see where THAT leads.