Tutorial 3: Create and assign contexts
Contexts are central to the way OmniFocus helps you find out what to do next: they represent the place, the tools, or the person you need in order to get something done. The contexts included in OmniFocus should give you an idea of what this means: any project you create may contain some things to do while you’re out running Errands, some Phone calls, some things to do at your Office, some things to talk to your Boss about, and so on.
Switch to context mode by clicking the Contexts button on the toolbar: 
While the planning mode’s blue sidebar holds your projects, the context mode’s purple sidebar holds your contexts.
OmniFocus comes with a few contexts already created for you. Add some new contexts by clicking the plus button below the sidebar, or double-click an existing context’s name to change it. Make as many contexts as you need for the various places and modes you have for doing work: Home, Office, Mac, Errands, Phone, and so on. You can always add more contexts later on when you find that you need them.
Now, go back to your projects by clicking the Projects icon on the toolbar: 
Open the pop-up menu on each action (where it says No Context), and choose from the contexts you just saw in context mode to assign a context to each action.
