1. Black Moleskine notebook where I write down ideas, and explain myself some complicated code for example. I use it more as a "mind-organiser" if I may say so...
2. Emacs' org-mode, where I write down my dev. progress on weekly level, lay down monthly plans and goals and write down some of the random stuff that I like to order into lists. And I use it more since I found out really good iOS app for org mode called "beorg". It is really awesome, I sync it with Dropbox and it works really, really well.
3. Apple Notes as my scribble kind of thing since synchronization works instantaneously between my iPhone and Macs. I use it mostly as my iPhone on-the-go noting system, and later on if I find something important I pass it to the org file or write it down into the black notebook.