David Allen sells a set of plastic folders with nice labels

IN, TO OFFICE, TO HOME, ACTION, READING

plus some blank ones you can add your own label to.

I use these to manage the paper I move around.

I also add the folders for projects I might work on while I’m out.

Thanks wreising! I had looked at Allen's products page but completely missed those folders. I'll look more closely.

Let me reframe my question less as one of "which folders to take" (though your answer is useful and welcome!) and more one of "if I define my briefcase as a GTD-style 'context,' how should I think about the work I do in that context?"

The times in my life I've felt most prepared to work while away from the office are also the times I've had an overstuffed bag and a bad back - I just carry too much stuff, and while that means I'm never without what I need, it also means I don't use much of what I carry. I feel happier (and healthier) when I carry less, but I'm always uneasy and occasionally find myself completely stuck because I'm missing a crucial piece of information.

Perhaps the answer is simply to prepare better, but I'm trying to suss out the best way to make preparations for work away from my desk.

I would try to define which Project folders to take with you by the Context of where you will be.

Namely, if you are going from the office to home, only take the projects you want to work on at home, and can work on at home. If you have a project that you can’t work on with the tools you have available at home, then it should weigh down your bag.

Also, if you have a project that you won’t have the energy required when at home, don’t bring that one either.

The series of questions to ask is similar to what you would ask yourself when trying to choose a next action to do.

What Context am I in?

How much time do I have?

How much energy do I have?

If you ask these questions with the place(s) you will be traveling to in mind, you should be able to reduce the number of files you choose to carry with you.