I must say that before I left I had a hard time figuring out what I needed to be able to travel by backpack and volunteer for a month in Sri Lanka. With previous travel experience, I simply guessed at what would work. I packed pretty light, but as soon as I showed up I knew I even still had too much. Here’s what I would recommend.
Pack everything into a backpack. Really. I’ve seen quite a few people around the country with suitcases, and it’s just so much easier to pack into a backpack. You’ll be able to travel around easier and you shouldn’t need more than what fits into a backpack anyways.
I brought two pairs of shoes and that really is all you need. For this particular project, I think hiking boots are heavy, hot and unnecessary. I brought simple running shoes and they do just fine.
I’m very happy I bought a pair of athletic sandals, because they are what I have worn the majority of my time here. They dry quickly, are durable, and are comfortable in the heat.
Snacks are always nice for long bus rides or times when the meals aren’t enough. Don’t bring many electronics. You’re going to a very isolated place and you don’t need to be connected.
I found a phone and a camera to be the main things I’ve used. Many people get a SIM card upon arrival. A phone comes in handy while traveling on the weekend as it can help you to reserve hotels, find train times, etc.
Lastly, bring a good guide book. I’ve never used one before on any of my trips, but I got one this time and it is very useful for a wide variety of things.