Some of us reject routines. We prefer to go with the flow and see where our days take us. However, this mindset is horrible for productivity. Those who are especially efficient follow pretty strict routines that take a lot of the guess work out of their days. Routines provide structure, which leads to you knowing what you want, how to get it and where things fit into your schedule.
One of the greatest aspects of having a routine is it decreases your risk of distraction. When you have designed a clear schedule for yourself and know exactly how you are going to spend your time, it's easier to stay focused and not get distracted.
A routine also sets you up for getting "in the zone." Once you assess your power hours, the time of day in which you are the most efficient, you can build your routine around that. This helps to get you at your optimal performance and a good routine will ensure that you find said zone every day.
Your routine can include working at a specific coffee shop every Wednesday or prepping for the following week every Friday afternoon. Whatever works for your productivity, make it part of your routine and make tweaks along the way. You'll find that a little structure can go a long way.