A few years ago I became interested in trying to have my work recognized. So I pursued having portfolios printed up, made plans for a web site and even a whole community surrounding it.
After a while it took the joy out of the art I loved, so I stopped all that and decided my art was all for me. Screw accomplishing, and to hell with recognition.
So now my work flow is a lot less deliberate, and I float in and out of various 'groups' of photographs, slowly getting negatives printed. It takes years of 'sitting on it' for me to truly start to appreciate what I shot, so it takes years for me to finish work, and I'm perfectly happy with that. In fact, it's exactly how I want it.
Some days I have spurts where I make four or five prints for a portfolio, and then I goof off printing something entirely different, just so that it doesn't feel like a chore, or a burden, but something rewarding and enjoyable. I work hard at my day job to have this enjoyment, so to me it simply must never become a chore or the whole thing completely loses its meaning.
In essence it's one picture at a time, when I feel inspired, for however long it may take.