An old adage, "plan your work; work your plan" has enduring business wisdom for today. Following a planned process makes particularly good sense in the constantly changing arena of software development.  

To keep work from becoming erratic or chaotic, we need process.  For software development, if you have a consulting partner, look to them for process guidance.  That said, while you may start with a partner's process, in the end, make it your own by continually improving upon it. 

I believe any smart process includes continually seeking and incorporating improvement based on feedback as well as just looking at what works.  At the end of each project, do a post-mortem.  Throughout the process, don't blame if mistakes occurred.  Instead, ask "what could be done differently next time to make it better?" 

Tom's Takeaway:  Work most effectively by following -- and continuously improving -- the work process.