Whilst travelling, I kept a journal and I have since written one part of my travels up as a book: http://www.weaveoftheride.com. However, I am now writing the second book, and I am looking for new approaches to write up my journal. Before I read through the journal and augemented what I thought was interesting with my own memories. However, I am considering whehter it might be more productive to first have a structural 'idea' and then write what I can remember around that, using my journal to trigger my memories. Does anyone have any experience and advice for this lengthy process?
As with a lot of writing advice out there, I'd suggest focusing on what you find interesting in your travels, and using this as your theme (or structure).
If the travel was only to a single location, then what drew you there?
Whether vacation or work, you or your business chose to go there - focus on those reasons as a starting point, and you can draw all sorts of comparisons between expectations and reality (as well as conclusions, should you be so inclined) which in itself is already a simple theme.
If the travel was multiple locations, what was the purpose? What was the plan? Was the purpose met, did the plan change?
Again, answering this will give you a simple structure in and of itself. I'm sure there are many other approaches.
Coming from a journalistic background (travel and alternative living), I would strongly suggest focusing on the message you want to deliver. You could start with your initial prejudice, innocence or ignorance and work toward your revelation (message).
I think it is also helpful to keep in mind what audience you are targeting. It will help you to omit details that may not be interesting for your readers.