I make sure to always have a paper notebook with me. I use it for anything from to-do lists to scribbling software designs and ideas. Often, I open it on the bu

I make sure to always have a paper notebook with me. I use it for anything from to-do lists to scribbling software designs and ideas. Often, I open it on the bus and don't even write anything in it. It has become a kind of token or reminder in that it makes me focus on ideas or planning my day instead of just getting lost in random thoughts. Although the latter is also important from time to time! Also, the current Economist. It's small and light and ensures I always have some good reading available.