Bill Atkinson...who was by far the most important Lisa implementor, thought that lines of code was a silly measure of software productivity. He thought his goal was to write as small and fast a program as possible, and that the lines of code metric only encouraged writing sloppy, bloated, broken code.
...He was just putting the finishing touches on the optimization when it was time to fill out the management form for the first time. When he got to the lines of code part, he thought about it for a second, and then wrote in the number: -2,000.
I'm not sure how the managers reacted to that, but I do know that after a couple more weeks, they stopped asking Bill to fill out the form, and he gladly complied.
In all cases, a commonplace is a method of compiling knowledge for later use. In digital or analog form, this continued growth of stored ideas and projects is a key driver of intellectual development. Any time you decide to work on a project, you should attempt to collect and categorise all information that is relevant and useful.
Methodically noting and filing resources is a sign of a mature and deliberate craftsman—it is an investment into future learning and projects. Before long, you will begin to reach the point where this collection generates projects and ideas with minimal effort; previously isolated ideas are consolidated and curiousity spurred on.
Effective writing stems from intelligently connecting the dots between the concepts you understand and can articulate. It stands to reason, then, that in order to generate more creativity you must not only add to a knowledge base, but deepen and expand the number of connections within the totality of the network. By establishing and explicitly mapping your knowledge, you allow yourself the freedom to remix information. You will often find that solutions come from previously unsuspected fields or topics—proving to be analogous in some shape or form.
Richard Feynman was fond of giving the following advice on how to be a genius: You have to keep a dozen of your favorite problems constantly present in your mind, although by and large they will lay in a dormant state. Every time you hear or read a new trick or a new result, test it against each of your twelve problems to see whether it helps. Every once in a while there will be a hit, and people will say: ‘How did he do it? He must be a genius!’