Presenting my productivity hack #2: write things down. This applies to everything: a thought that you have that you want to explore later, a task that needs to be done at some point, something that is bothering you or some new idea you have. Writing it down helps you 'download' the thought onto paper, and stop thinking about it, enabling you to focus your mind and energy on the task at hand.
I use this hack constantly - there is always a pen/pencil and sheet of paper next to my computer. For this purpose, I prefer paper over note taking applications like Evernote, which I use for almost everything else. Paper and pencil also lets me physically scratch things out when they are done, giving additional satisfaction on a small task accomplished or idea executed.
Next up: how to eat unlimited ice cream and gain no weight.