I'm the kind of person that starts with a premise and quickly begins working out details. After getting the bare minimum worked out, I get to work. I make sure to have one year's worth of comic finished before I begin posting and also that the end of the year comes with a completed arc. That way, I not only have time to edit everything, but also it gives me a chance to start/finish the next season.
My writing process revolves around making the panels to a page first. Sometimes I start with dialogue, sometimes I start with the panels themselves. Each page starts with a 6 panel grid and adjust it as I see fit.
After I figure all that out, I draw the appropriate pictures, scan them into my computer, and adjust each picture to fit within the decided panel size. Then I trace.
After all the tracing and finishing touches (color, background, etc.) are complete, I make whatever adjustments I need to and... Ska-doosh!
My current series is a lot easier because all the panel sizes and shapes remain more or less the same from strip to strip.